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  1. #1
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    LG Multisplit ongoing issue... slowly getting there I think!


    Hey everyone,

    Thought I would start a new thread following on from...

    http://www.refrigeration-engineer.co...ad.php?t=26871

    Engineer fixed sticking EEV on one unit by swapping over to unused port on outdoor unit... this fixed the issue in cooling however still the problem in heating as described below.

    As the units are running in heating on a night we are finding that the unit that was swapped over onto the unused port when this reached thermostat off the coil temp drops to about 26C and the fan comes on now and again to remove the build up of it. I understand the EEV on the unit that is thermo off is 10%.. fair does. This unit is approx 10metres from the outdoor unit.

    If one of the other units is at thermo on and the lounge unit which is only 2metres from the outdoor unit is at thermo off the fan runs constant on this unit and the coil will get upto the same temperature as the unit that is at thermo on. This then causes duty loss on the unit that is at thermo on because the fan is constantly running on it.

    Engineer has checked the eevs and as these are closing in cooling properly in heating they should be functioning as needed. We also dont think its a control issue as the other units behave as they should as their coils do not build up enough heat input at thermostat off from the EEV 10% opening to keep the fan on... which is how it is designed to run... the issue is with the unit on the shortest pipe run.

    LG specify a minimum pipe run of 5 metres between indoor and outdoor unit so engineer has said that it is possible that because of the short pipe run pressure is or isnt dropping (cant remember which he said) by the time the refrigerant has travelled the short 2 metres to the unit that is at thermo stat off, and because the fan is on this causes the pressure to drop/not drop further in the system causing performance loss across the unit that is still at thermo on... does this sound right... its the only thing left that could possibly be wrong. He said to put a coil of pipe behind the unit to bring it upto the required min pipe run then the pressure will/wont drop (cant remember which) in the extra pipework meaning the performance shouldnt drop off as the fan wont be running all the time as less heat input into the coil at thermo off.

    We have never increased the pipe run on the 2 meter unit as other engineers have never said to do this.

    When all other units are at thermo off and the lounge unit (2mtr run) is at thermo on we get air offs of about 43C which is great and the other coils do not get hot enough to keep the fan on all the time whereas if its the lounge unit at thermo off and one of the other units calling for heat the coil on the lounge unit still gets enough heat input into the coil to make the fan stay on all the time.

    Thoughts please...

    as usual thanks for any advice you give.

    Kind regards

    Richard.



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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Hi Richard, good to hear that things are progressing somewhat.

    Thinking out loud, as they say.....

    The fact that the fans run is not indicative of a controls fault simply one of refrigerant flowing where you don't want it too.

    Are you prepared to modify the system outside of the LG scope?

    A. When a unit goes thermo-off can you interface with this control signal somehow? In other words, could you connect a relay which would switch over when the 'stat goes off.?

    B. If yes, then see about fitting shut-off solenoid valves in the pipework so that the flow is stopped when at thermo-off.
    Brian - Torquay, Devon, UK
    I have to stop saying "how stupid can you be?" to my co-workers.
    They're starting to take it as a challenge...

    BASIC MAINTENANCE. If it doesn't move and it should then use WD40. If it moves but it shouldn't then use Duct Tape.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Brian_UK View Post
    Hi Richard, good to hear that things are progressing somewhat.

    Thinking out loud, as they say.....

    The fact that the fans run is not indicative of a controls fault simply one of refrigerant flowing where you don't want it too.

    Are you prepared to modify the system outside of the LG scope?

    A. When a unit goes thermo-off can you interface with this control signal somehow? In other words, could you connect a relay which would switch over when the 'stat goes off.?

    B. If yes, then see about fitting shut-off solenoid valves in the pipework so that the flow is stopped when at thermo-off.
    Good evening Brian

    I trust to find you well?

    Thank you for your response, I would be prepared to look at these options as everything else has been tried but would like to see if increasing the pipework length to the minimum that lg specify. Would this cause problems when the unit goes into defrost? Also think that modifying the control signal as my engineer would prob charge me a small fortune to do that... hes good at what he does mind.

    The fan runs on the other units occasionally when they are at thermo off when the coil gets a build up of heat but no where near as much as the unit that is on the 2mtr pipe run... where when it reaches thermostat off there is still enough heat build up in the coil to keep the fan on constantly with an air off of 38C matching the unit that is calling for heat. This in turn raises the room temperature higher and higher until the other units are all at thermo off.

    The other units at thermostat off the coils are at about 27C and the fan only comes on for about 10seconds every few minutes to clear that heat build up but this doesnt cause the room temp to rise even though the rooms are smaller. The fact this is only happening on one unit suggests that it is piping length issue but I need to understand how the short pipe work might cause a build up of heat in the coil enough to keep the fan running and cold air prevention off.

    So do you think the short pipe run could be causing this heat build up in the coil when the eev is supposed to only be 10%? You mention its not a controls issue so all units should be behaving the same 2 out of the 3 are so the EEVs on them are open the same but then these units are on a longer run.

    Increasing the pipe run might be enough to stop as much refrigerant getting to the coil in one go maybe?

    Thank you once again.
    Last edited by back2space; 27-09-2010 at 01:00 AM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    BY saying it isn't a controls issue I mean that the fans are responding correctly to the coil temperature.

    Possibly the shortened pipe length is not allowing the heated gas time to cool/condense before reaching the indoor coil.
    Brian - Torquay, Devon, UK
    I have to stop saying "how stupid can you be?" to my co-workers.
    They're starting to take it as a challenge...

    BASIC MAINTENANCE. If it doesn't move and it should then use WD40. If it moves but it shouldn't then use Duct Tape.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Brian_UK View Post
    BY saying it isn't a controls issue I mean that the fans are responding correctly to the coil temperature.
    What I meant when I suggested a controls issue was that the EEV on that unit might be being told to open more than the other units at thermo off.

    The fact though in cooling it shuts fully at thermostat off and the coil doesnt get cold means that refrigerant isnt flowing through the coil... there shouldnt be any difference in heating it should be opening/closing as far as the system tells it to without difficulty. I agree with you I dont think its a eev/control issue.

    Quote Originally Posted by Brian_UK View Post
    Possibly the shortened pipe length is not allowing the heated gas time to cool/condense before reaching the indoor coil.
    Yes I agree this is the theory that my engineer put to me also and said that with a longer pipe run the pressure will drop in the pipework so not as much gas will reach the indoor unit... not sure how this affects the rest of the system and what a longer pipe run would do?

    Currently because the fan is continuining to dissipate heat from the coil that is at thermo off what would be happening to the system for capacity to drop off at the unit that is still calling for heat?

    Does this do something to the system pressures or something?

    I mean if we fitted a longer pipe run so that the gas cooled/condensed before it got to the indoor unit would this not do the same to system conditions as the gas cooling/condensing in the indoor unit because the fan is dissipating the heat?

    I am trying to get my head around what may be happening and trying to compare it against having the longer piperun.

    Eg if I dont have the longer pipe run then the heat build up is being removed at the indoor unit as apposed to length of pipe outside... or if I do have a longer pipe run the gas loses momentum and doesnt have enough momentum to move to the indoor unit so in affect its moving very slow to the indoor unit? I know gas moves easier than liquid.

    I could get the engineer to come and add extra pipe work coiled up behind the unit, unsightly I know but no where else to route it.. if this doesnt work then its more money spent that wasnt needed... so need to get an understanding of how shorter pipe run might affect the heating before I make the decision to get him back out.

    Completley baffled but I think I am onto something just dont have enough understanding of how the system works to get my head round it.

    LG havent explained unless I get the engineer to call them but have said that a short pipe run could cause adverse operation of the system.

    Again, thanks for your help so far...

    Richard.
    Last edited by back2space; 28-09-2010 at 10:13 PM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    It's difficult without knowing the system equipment layout but we'll have a go...

    Cooling Mode -
    Outdoor unit - Solenoid valve - pipework - indoor unit EEV - indoor coil - pipework - outdoor unit.
    Indoor EEV has liquid feed from outdoor unit and expands liquid into the indoor coil.

    Heating Mode -
    Outdoor unit - pipework - indoor unit coil - indoor unit EEV - pipework - outdoor unit solenoid valve.
    Hot gas runs through the indoor coil before being arrested by the EEV. EEV may not have a liquid seal on it so will bleed vapour.

    Short pipes have not provided sufficient resistance to the hot gas so coil operates at higher pressure/temperature.

    I could be wrong though.
    Brian - Torquay, Devon, UK
    I have to stop saying "how stupid can you be?" to my co-workers.
    They're starting to take it as a challenge...

    BASIC MAINTENANCE. If it doesn't move and it should then use WD40. If it moves but it shouldn't then use Duct Tape.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Brian_UK View Post
    It's difficult without knowing the system equipment layout but we'll have a go...

    Cooling Mode -
    Outdoor unit - Solenoid valve - pipework - indoor unit EEV - indoor coil - pipework - outdoor unit.
    Indoor EEV has liquid feed from outdoor unit and expands liquid into the indoor coil.

    Heating Mode -
    Outdoor unit - pipework - indoor unit coil - indoor unit EEV - pipework - outdoor unit solenoid valve.
    Hot gas runs through the indoor coil before being arrested by the EEV. EEV may not have a liquid seal on it so will bleed vapour.

    Short pipes have not provided sufficient resistance to the hot gas so coil operates at higher pressure/temperature.

    I could be wrong though.
    I should have said the EEVs are in the outdoor unit.

    Just done a little test, disconnected the fan motor on the 2mtr run unit so that at thermostat off the fan cannot run. Now normally with the fan running the unit furthest away the coil will drop to about 38C and match the 2mtr run unit with the same air off, now having the fan motor disconnected on the 2mtr run so the coil retains its heat means the unit furthest away maintains its coil temp of 47C and didnt drop at all.

    I also notice that with this 2 mtr run in heating mode the refrigerant is noisy when it circulates through the indoor unit when it is turned off as if theres too much velocity in the pipework.

    I think your onto something, the short piperun isnt providing sufficient resistance so its all flowing to its easiest route the 2mtr run and then causing performance drop off on the unit furthest away.

    We know for certain there is nothing wrong with the EEV as this works fine in cooling so it must be the pipe run that is not making any resistance to hold back the gas so its just flowing through the indoor unit fast at which the indoor units response is to get rid of the heat from the coil.

    The wall mount unit at thermostat off keeps the fans off no matter how hot the coil is so if I had wall mounts in the other rooms then there would never have been this problem as the software in the unit does not run the fans unless its thermostat on.

    Engineer coming back on Friday to hopefully install 6mtr worth of pipe work to the short one and hopefully this will resolve our problems once and for all.

    Shame on LG though at the beginning and the installing engineer for saying thats how it was supposed to operate!
    Last edited by back2space; 29-09-2010 at 11:49 PM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Little update

    Engineer was here 3 hours today, cost me £140... waste of money.

    He totalled the pipe work on the unit to 8 meters to bring it upto LG spec.

    We really did think this would resolve the issue but truth be told it has made no difference whatsoever so a 2 meter pipe run makes no difference what soever to the performance of the system.

    So we have exactly the same issue which means more engineer time to investigate only this time LG will talk to us because we have brought it upto spec.

    I got lg technical on the phone when engineer was on site to speak to him, after he left LG stated they asked engineer to check the pipe temperatures, engineer only checked air off temps and didnt do as they had asked. I rang LG back and they said engineer didnt sound very enthusiastic to do what they were asking... I said well if you dont think he was enthusiastic then you can imagine what all the other guys were like as this guy is pretty good.

    Engineer is now convinced that the EEV is staying open on that unit but only way to check this is by changing the problem units pipework over onto a working unit, meaning a further pump down and another 2 hours work. LG say he can push the pin down by taking the head off... so why didnt he do this on his first visit when I paid him £80 to investigate a sticking valve when he said he coudlnt get to the pin?

    I queried if it was a valve issue then why is it closing down in cooling at thermostat off and the coil does not get cold... they state they need the engineer to check the valve heads etc and push the pin down to check nothing is obstructed... waste of time I think as it works in cooling. I advised them what if the valve is free to move etc they then said that they would have to look at the control strategy of the system.

    The system is 2Ĺ years old now...

    I raised the idea that the strategy of the floor mount units is to keep the fan running if the coil is above a certain temp in thermostat off whereas the wall mounts keep the fan off at thermostat off no matter how hot the coil gets. Even if the valve is letting to much gas through to the coil its the fan running all the time that is zapping duty from the other units as we proved when we disconnected the fan motor on said unit.

    So I am back on the war path again with how rubbish quality lg units must be to have such a poor control strategy on the floor mount units. Also these issues have been there since day 1 2Ĺ yrs ago!

    If they were all wall mount units (cheaper unit all round) then we would never know if a valve was sticking open in heating mode as the fan would only run when the unit was calling for heat.

    What do you think...
    Last edited by back2space; 05-10-2010 at 03:28 AM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by back2space View Post

    What do you think...
    I'd actually be very annoyed myself to have spent all that money and achieved no results

    PITA Richard, but you're convincing me of what I need to avoid at all costs in the future!

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Andy_WSM View Post
    I'd actually be very annoyed myself to have spent all that money and achieved no results

    PITA Richard, but you're convincing me of what I need to avoid at all costs in the future!
    Key word... LG

    I am very annoyed, I have a good engineer this time round though but it just shows that all of them I have had so far have been no good.

    My engineer is under instruction now to resolve this with LG, I need to get it fixed I cant spend this much money so far and just give up now it needs resolving and the job closing.

    LG suspect either the valve is faulty (doesnt explain why it is closing in cooling properly) or its a control issue which again doesnt tally with why the other units and valves work ok.

    If you have a good engineer now then stick with him as he will know your system.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    UPDATE:

    Engineer attended Friday last week to check the valve head on the unit... he took the top of the head off and it was all corroded inside.

    We have worked out that there is a design issue with the outdoor unit, in that the valve head which has a hole in the top of head (not sure what for as all the others do) sits directly below the main header pipe inside the outdoor unit.

    In cooling mode this pipe sweats with condensate which has been dripping down onto the valve head and draining through into the head corroding it and LG say this corrosion will have been changing the voltages so that the valve will not respond as it should as the signal will not be right

    So he has swapped the valve head over with one of the working heads which has improved things but the coil is still getting warm on the affected unit... not as much so the fan stays running all the time but enough so that the fan stays on more than it should, which then zaps heat from the other coil.

    Switch that coil off and the air off temp increases on the other unit that is calling for heat.

    Hes going to come back out on the 19th to check the voltages on the head of the valve to see if its working properly.

    Engineer is as keen as me to get this resolved and he agrees with me that the cowboys who fitted the system are out of business now for a reason. He said he has stuck with this since he came out first time because he could see that I knew what I was on about.

    All the idiots who have been back to it in the past and have always fobbed me off with excuses despite me knowing what I am talking about.

    As the main cause of the problem from day one seems to be a design issue then responsibility should fall with LG for all this has cost me.

    The unit has warranty left on it till June next year but I bet theres not a cat in hells chance of me getting some money back on the repairs because it comes down to a design fault.

    None of the other valve heads are affected as they are in another position away from the header pipe.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Glad you are making progress Richard - but what a pain in the **** it has been for you so far!

    (My Fujitsu is working lovely thanks )


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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Andy_WSM View Post
    Glad you are making progress Richard - but what a pain in the **** it has been for you so far!

    (My Fujitsu is working lovely thanks )

    Oh I know... most annoying thing is that it just shows the poor design of LG because this wouldnt have happened in the first place but then on the other hand engineers havent wanted to work on the damn thing either because its LG, every engineer who has been out as soon as they learned it was LG have not wanted to bother stripping it apart etc.

    My engineer says himself to replace the EEV would be a real pain.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Well other night when it was 8C outside with one unit turned on air off temp wouldnt get above 38C... Unusual as when one unit is on the air off temp goes to 47C-50C.

    So powered it off at the mains for a few minutes, turned it back on and air off got upto 48C... Whats going on there then!

    Hate lg, hate lg, hate lg!!!
    Last edited by back2space; 17-10-2010 at 10:16 PM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by back2space View Post

    Hate lg, hate lg, hate lg!!!
    LOL. Wouldn't be so bad if you hadn't poured money at it!

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Andy_WSM View Post
    LOL. Wouldn't be so bad if you hadn't poured money at it!

    I know

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by back2space View Post
    Hate lg, hate lg, hate lg!!!
    Gotcha !

    At last, you've admitted it in public.

    Sorry B2S, hope it resolves itself.
    Brian - Torquay, Devon, UK
    I have to stop saying "how stupid can you be?" to my co-workers.
    They're starting to take it as a challenge...

    BASIC MAINTENANCE. If it doesn't move and it should then use WD40. If it moves but it shouldn't then use Duct Tape.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Brian_UK View Post
    Gotcha !

    At last, you've admitted it in public.

    Sorry B2S, hope it resolves itself.
    I cant even begin to say how I am with them!

    I would never have lg again!

    I have 2 lg tvs and they have been spot on so I dont get why its so poor qaulity stuff as the tv is fine.

    Why oh why after a reset at the mains did the air off temp jump back up. Makes no sense.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    I sometimes wonder with the electronics that are incorporated now don't have the software to do them justice.

    Do they run for so long and start thinking that the start point for the next adjustment action is where it has been for the last few hours when, in fact, it has been sat at +15 above the start point. A reset then puts it back to zero again.

    It's the silly things that even the big ones mess up on..... I've just replaced my broken PC with a new one which runs Windows 7.

    Run a Windows update and at the end it says - restart - click here.

    So you click on restart and Win 7 then tells me that it is waiting for a program to close before it shuts down. Yup, you've guessed it - the program it is waiting for is the updater program. - I rest my case.
    Brian - Torquay, Devon, UK
    I have to stop saying "how stupid can you be?" to my co-workers.
    They're starting to take it as a challenge...

    BASIC MAINTENANCE. If it doesn't move and it should then use WD40. If it moves but it shouldn't then use Duct Tape.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Brian_UK View Post
    I sometimes wonder with the electronics that are incorporated now don't have the software to do them justice.

    Do they run for so long and start thinking that the start point for the next adjustment action is where it has been for the last few hours when, in fact, it has been sat at +15 above the start point. A reset then puts it back to zero again.
    Not sure I understand Brian? Sorry it has been a heavy weekend

    I understand about the pc side of things... im forever getting windows updates all the time then it asks u to reboot.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Hi Richard,

    Do you have any update with this system?
    I have a few question? Firstly what is the model #'s of both outdoor and all indoor's connected. I would like to know the indoor unit diversity connected.
    Secondly, have anyone advised you that it is possible to connect a service software to the system. This should be available through LG. It will give a clearer indication of the parameters during operation and hopefully pinpoint anything abnormal.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Ross View Post
    Hi Richard,

    Do you have any update with this system?
    I have a few question? Firstly what is the model #'s of both outdoor and all indoor's connected. I would like to know the indoor unit diversity connected.
    Secondly, have anyone advised you that it is possible to connect a service software to the system. This should be available through LG. It will give a clearer indication of the parameters during operation and hopefully pinpoint anything abnormal.
    Hi there

    Thank you for the reply: THe update is this still:

    Quote Originally Posted by back2space View Post
    UPDATE:

    Engineer attended Friday last week to check the valve head on the unit... he took the top of the head off and it was all corroded inside.

    So he has swapped the valve head over with one of the working heads which has improved things but the coil is still getting warm on the affected unit... not as much so the fan stays running all the time but enough so that the fan stays on more than it should, which then zaps heat from the other coil.

    Switch that coil off and the air off temp increases on the other unit that is calling for heat.

    Hes going to come back out on the 19th to check the voltages on the head of the valve to see if its working properly.

    None of the other valve heads are affected as they are in another position away from the header pipe.
    I wasnt aware that you could connect a laptop up but I bet this is expensive and LG would charge a fortune for one of there engineers to visit and I dont think I should have to pay for it.

    INdoor units are MV12AH x2 and MS12AH x1 & Outdoor unit is FM25AH UE1.

    If all three are running together then they are over indexed for the outdoor unit (over capacity) but fact is I get better performance and higher air offs if all three are running together than if 2 are at thermo off and just 1 is running at thermo on.

    When I first turned one of the units on tonight I got an air off of about 45C, when it cycled off and came back on later I was getting max of 38C. So I thought for a test put it to 30C and then the air off in theory should rise to 45C or higher as the compressor should be fully ramped up. Air off didnt change it stayed at 38C. Even when I switched on one of the other units air off did not climb and one unit would not shift out of low fan speed despite being set at 30C as the air off was only 32C which if your sat near the unit 32C air feels draughty and not pleasant. Compressor was ramped up though as it would be for 30C. Thing is this just makes the unit run endlessly for hours trying to achieve set point because air offs are so poor.

    Few weeks ago running one unit I would get 47C no matter what.

    Something is seriously messed up on this system.

    So annoying... I hate LG.

    So if its 7C outside then whats it going to be like when its 0C outside, its rated down to -15C so when i put it upto 30C air offs should be really warm.
    Last edited by back2space; 19-10-2010 at 11:34 PM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Richard,

    As with LG spare parts the service software is relative cheap to purchase. Here in Oz it is approximatley AU$200. Not bad considering it connects across LG's whole product range from Single Split, ducted, Multi to VRF. Maybe you can enquire through your LG rep. If the Engineer you are refer to attending site is from LG then I am surprised he has no Laptop and the service software. I would be questioning on why not. These systems have a number of thermistors and it takes only one to be out of calibration for the system to go into a saftey control parameter. If I remember correctly the FM25AH has 2 compressors and with one faulty thermistor this may result in the 2nd compressor not operating. Let me know how you get on?

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Ross View Post
    Richard,

    As with LG spare parts the service software is relative cheap to purchase. Here in Oz it is approximatley AU$200. Not bad considering it connects across LG's whole product range from Single Split, ducted, Multi to VRF. Maybe you can enquire through your LG rep. If the Engineer you are refer to attending site is from LG then I am surprised he has no Laptop and the service software. I would be questioning on why not. These systems have a number of thermistors and it takes only one to be out of calibration for the system to go into a saftey control parameter. If I remember correctly the FM25AH has 2 compressors and with one faulty thermistor this may result in the 2nd compressor not operating. Let me know how you get on?
    The FM25AH UE1 has only one compressor, it is the year before this model was produced where they had two compressors, a fixed speed and inverter.

    I have sent LG an email this morning, pretty much pleading with them that they now resolve this I simply cannot afford to keep throwing money at it and I need a reliable heat source this winter since its forecast to be a cold one.

    Hopefully I may get somewhere, my engineer says that it could be something like the eev that is faulty and not closing but then we could end up replacing it and it still doesnt correct the issue meaning more time and money wasted.

    I think its high time someone came out and connected a laptop to it to check exactly what it is playing at.

    I think its a control issue personally but having had the main pcb replaced 8 months after it being installed and exactly the same issues immediatly after suggests that it is not a malfunction of the pcb or other parts but a control issue.

    Here is a copy of the email I have sent to LG Air Con technical, straight from the heart:

    Good Morning,

    I am emailing you & pleading with you to help me get this resolved, this is all starting to make me very ill. It has been going on nearlly 3yrs and should have been resolved a long time ago.. I know in between there has been some dodgy engineers who havent wanted to resolve this but there has also been a good handful that have wanted to resolve it. It is becoming even more of an issue as we approach winter again... this should never have gone on this long and responses from LG in the past have been most unhelpful up until dealing with yourself who seems interested and wants to help. It is now time I feel that LG deal with this as a proffesional company and rectify once and for all.

    System is not working well at all again and im another £250 short.... engineer feels that all the EEVS cant be faulty so its either forking out more getting them all replaced and then finding that its still the same or pretty much pleading with LG that this is a control issue, as all the factors and engineers that have attended have said we seem to be going round in circles and there is more to it. Yes one of the valves has been sticking and that has now been rectified but even that unit is poor on heating. The system behaves 100% in cooling and all valves close down when units are at thermo off and does exactly as it should so we know its the heating control strategy. Engineer is happy to work with the LG engineer but I am told on the forum that someone can connect a laptop with service software on to the outdoor unit to see operating perameters. Please please can we go down this route so that engineer can check the software and correct if need be and diagnose this system properly. EVerytime my engineer is spending a lot of time stripping the system down and he says it is very awkward to get to the parts so time and ££ is spent doing this as well. It makes sense that it is a control issue as with all 3 indoors running the outdoor unit is undersized but actually with all 3 units calling for heat it performs better (higher air off) than if 1 or 2 units were running.

    In total I have spent near to £2000 in engineer visits and not one has resolved it. I am pretty much pleading with you that LG at least do something to help me. The heating is needed I have a poorly member of family who lives here with health issues and needs reliable heating. You know I was warned off LG by people on the forum, however I am a very loyal LG customer owning 2 LCD tvs, microwaves and other appliances they have been spot on... the air con leaves something to be desired.

    The fact that one of the valve heads was corroded because of a design issue is also not very good on LG's part. THe header pipe that carries cold refrigerant runs directly over one of the EEV heads and in cooling this pipe sweats and water has been dripping down onto the head and corroded it. It would have made sense for this pipe to have been insulated or not running directly over the heads and corroding one of them that is directly underneath.

    Given that this unit is still in warranty till next year (installer gone bankrupt) I think it would be a good gesture of goodwill to send one of their engineers to investigate. Given this has gone on for nearlly 3 yrs and still not resolved despite endless call outs.

    My engineer has checked voltages and all seem to be ok there and swapping the valve heads about makes no difference. This leaves one thing, the control strategy which is something nearlly all the engineers have suggested who have been out.

    I have even had personal emails from Graham Hendra when he was dealing with this and telephone calls. I have had Ken from LG technical on previous occasions tell me there is nothing wrong with the system and that its not close control and that I should rip it out and install storage heaters... not very proffesional really. Especially when engineers have stated there is issues with it. Even p_p from this forum visited and he said that it was not working right.

    Just to bring you upto date on the long drawn out process... The ammount of posts I have had to put on forums about the issues are endless... Here are a few... I can even forward you the masses of emails between me and the installer him claiming there is nothing wrong but then my independant engineers who have attended all say something wrong.

    I have had lies upon lies from the installing engineer even at one stage after I demanded that he attend and rectify or I was going to take legal action he agreed it was faulty and then said that LG were going to send a new board with different perameters as was a control issue.

    http://www.refrigeration-engineer.co...ad.php?t=27723 - Latest forum discussion.

    http://www.refrigeration-engineer.co...ad.php?t=17171 - The start of a discussion online from 2009.

    http://www.refrigeration-engineer.co...6&postcount=50 - p_p's diagnosis after visiting...

    http://www.refrigeration-engineer.co...9&postcount=54 - This poster even suggests that the software control is bad as my version of the multisplit was quite a new model when it was released. This is believable as the system is certainly not controlling right and never has.

    Email from Graham Hendra promising some resolution will be found 21/03/09:

    "Today I spoke with the installing contractor

    He will be in contact about your machine together some resolution will be found

    regards

    Graham Hendra
    General Manager Airconditioning LGEUK"


    Please Andrew will you give this some steam now to get this resolved I dont think I can take this much further, I have had to sell things to pay for the call outs because of lack of heating performance and I cant have another winter of having to use electric heaters to assist the system, last winter was very expensive when we invested in a system that should have worked properly from day one. Surely newer models have different control software.

    Kind regards
    Richard.

    Last edited by Brian_UK; 14-01-2011 at 08:01 PM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Richard,

    The info I have for the FM25AH-UE0 shows 2 compressors. A question, does the front panel have a sticker 'MPS inverter' ? This indicates it is a 'multi power system' and will have multiple compressors. I still suggest starting with the service software. This will indicate all parameters in the system. If you have a laptop and LG are not willing to attend site I would pressure them to supply it to you. It is quite simple to operate and understand. It comes as 2 parts - Cable and module box - software and hard lock key.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Ross View Post
    Richard,

    The info I have for the FM25AH-UE0 shows 2 compressors. A question, does the front panel have a sticker 'MPS inverter' ? This indicates it is a 'multi power system' and will have multiple compressors. I still suggest starting with the service software. This will indicate all parameters in the system. If you have a laptop and LG are not willing to attend site I would pressure them to supply it to you. It is quite simple to operate and understand. It comes as 2 parts - Cable and module box - software and hard lock key.
    Hi Ross

    Thank you for your reply, I can guarantee that mine is the 1 inverter compressor model.

    The sticker on the front says "inverter". I know previous models had 2 compressors but this was the first model that only uses 1 compressor... FM25AH UE1.

    As I say I have emailed LG technical but not had response yet but will request software if they still wont send anyone.

    I am quite competent with software so will have no problems connecting it to a laptop and then perhaps working with LG technical to see what the perameters are coming back as.

    I think I am being very fair in my email.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Further info on the software and cable.

    Available through sales as; Sales item#PRCTSL1-software, #PRCTFE1-module and cable or through spare parts #5001A20200F-software, #5001A90032E-module and cable.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Ross View Post
    Further info on the software and cable.

    Available through sales as; Sales item#PRCTSL1-software, #PRCTFE1-module and cable or through spare parts #5001A20200F-software, #5001A90032E-module and cable.
    Thank you, I will certainly not be paying for it though.

    I will be requesting that they at least send it to me.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Just check there is a connection on the outdoor PCB either labelled CH-PC or CN-LGMV. I'm 99% sure there should be but best to double check as I know the software works for the FM25AH-UE0

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Ross View Post
    Just check there is a connection on the outdoor PCB either labelled CH-PC or CN-LGMV. I'm 99% sure there should be but best to double check as I know the software works for the FM25AH-UE0
    Hi Ross

    Yes it does have a connection for that.

    I tried ringing my contact in LG technical today... the guy who me and my engineer have been dealing with answered he was in hospital for the last 4 days? So was unable to help... but says he will read my email when he returns.

    I then decided to ring the main office number and spoke to a most unhelpful and rude man who was not even aware that his colleague was off sick and that it was news to him (me thinks I am being fobbed off).

    He didnt want to help and says I will have to wait until my contact is back in the office. I said the unit is still under warranty and he said that I have to ring the distributor. I said the original installer is bankrupt.

    What an absolute joke. I rang Dean & Wood, who dont want anything to do with and say that warranty is void if the original installer is out of business. Dean & Wood also stated that if the original installer had told them within good time that the outdoor unit was faulty rather than him messing around replacing boards and the fault still being there then they would have just replaced the outdoor unit.

    If this isnt resolved I will be going to Citizens Advise and maybe a solicitor as the unit isnt fit for purpose.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Still nothing from LG.

    Sent them a further email: I think the cheaper solution in the long run is to get the fans to stop on the floor units, the wall mounts have the fans turn off at thermo off.

    Not sure how else to get the fans to stop other than as I have suggested below.

    "
    Hello,

    Haven't heard back from you but my engineer says we just need to be able to get the fans on the indoor units to stop when they reach thermostat off. The floor mounts are causing the problem as the fans continue to run when the coils are warm and this takes heat from the rest of the system that still needs it. The wall mounted unit doesn't. The fan only runs at thermo on and then samples the air temp every 4 minutes.

    He has shown this is the issue as we disconnected the fan motor at thermostat off and then the coil temps went affected on units still at thermo on.

    Question is how can we resolve this it is obviously a flaw in the control software that doesn't keep the fans off. The coils on both floor mount and wall mount run at same temp at thermo off yet the the wall mount doesn't keep it's fan running.

    Would a wall mount pcb fit the floor mount unit given that they are the same size. 3.5kws? Or would the connectors not fit. In theory it should as the same remote control will run any of the units. Also are the fan motors controlled differently?

    This I think would be a good solution as disconnecting the fan motor proved that there was no performance loss on the other units. If not could You guys change something in the software to keep the fan off? "
    Last edited by back2space; 26-10-2010 at 07:49 PM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Hi Richard,

    I think you are thinking too deep here! As I suggested before talk to LG about getting the service software connected to the system.. It is going to make it far easy to diagnosis. As for the controls software flaws you suggest-it maybe a parameter input they is causing the problem. It only takes one! Not the software itself.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Ross View Post
    Hi Richard,

    I think you are thinking too deep here! As I suggested before talk to LG about getting the service software connected to the system.. It is going to make it far easy to diagnosis. As for the controls software flaws you suggest-it maybe a parameter input they is causing the problem. It only takes one! Not the software itself.
    Yeh but both floor mount units are doing the same thing so theres something in the software that doesnt hold the fans off once they reach thermostat off.

    The wall mounts the fan stays off and comes on very low every 4 minutes to sample the air temperature whatever temp the coil is at.

    LG are not coming back to me with a response so I doubt very much they will send the service software.

    I think the long term solution is going to be finding a way to keep the fan turned off at thermo off.

    All the valves appear to be have the same way, the wall mount gets as hot as the floor mount unit at thermo off if put into fan mode so they all receive same ammount of refrigerant however the floor mount that was switched over onto an unused EEV the coil air off will not rise above 29C for some reason so very poor heating from this coil.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Richard,

    I'm confused.. What is this the issue with the system. Is it poor performance (ie: insufficient heating) or indoor fans not cycling 'off' when unit reaches setpoint therefore having a cold draft affect?? From my experience with these systems it is generally a basic problem (eg: thermistor out of calibration) that can cause performance issues that is why I am suggesting having the Technician use the service software.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Good news:

    Received this response today from LG:

    Dear Richard,
    After reading your last email and only returning back to work today I was under the impression that we were on the way to resolving this issue as the last conversation I had with you or your engineer was that he found the corroded valve coil and was going to test the coilís operation, since I have not heard anything back I thought it was resolved, However as there still seems to be a problem I am willing to come up to you and examine your air conditioning unit to see if we can get to the bottom of the problem, I am busy this week as I have only returned after being in hospital but if you are available next week I can come up and have a look,
    I hope this is of help,
    Last edited by frank; 14-01-2011 at 10:42 PM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    ^^ YeeHah ! (We hope)
    Brian - Torquay, Devon, UK
    I have to stop saying "how stupid can you be?" to my co-workers.
    They're starting to take it as a challenge...

    BASIC MAINTENANCE. If it doesn't move and it should then use WD40. If it moves but it shouldn't then use Duct Tape.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    are the 2 units with the same model no. giving you the problem? try pumping down all the units. with no pressure in the head units and guages on 2 separate suction ports, open each liquid line individually. see if there isnt a crossing over of pipes eg. liq line from system 1 crossed with liq line system 2. or you could just pump the unit down, remove all the pipes and run nitro through individual head units to make sure each set of pipes is going where they are supposed to.
    you would think someone would have picked it up earlier but i'd give it a go..
    as for the lgmv (lg computer analyser) i wouldnt bother. pipe thermisters should be 5-10k at about 20c.
    if the indoor fans come on as soon as you turn the unit on from a cold start on heat, then the indoor pipe thermisters are ****ged.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by rxv88u View Post
    as for the lgmv (lg computer analyser) i wouldnt bother.
    I don't agree with what you suggest above........Think about another analogy. You take your car whether it's a Ford, Toyota, etc with what you believe to be an ongoing problem to the dealership. You know their workshop has available the computer software (which every car dealership has these days supplied by the manufacturer) to connect and the Technician turns to you and says I wouldn't bother with using it! Whether they find a fault or not I think for peace of mind for both the customer and the Technician it is necessary to use in a case such as this.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by rxv88u View Post
    are the 2 units with the same model no. giving you the problem? try pumping down all the units. with no pressure in the head units and guages on 2 separate suction ports, open each liquid line individually. see if there isnt a crossing over of pipes eg. liq line from system 1 crossed with liq line system 2. or you could just pump the unit down, remove all the pipes and run nitro through individual head units to make sure each set of pipes is going where they are supposed to.
    you would think someone would have picked it up earlier but i'd give it a go..
    as for the lgmv (lg computer analyser) i wouldnt bother. pipe thermisters should be 5-10k at about 20c.
    if the indoor fans come on as soon as you turn the unit on from a cold start on heat, then the indoor pipe thermisters are ****ged.

    All this has been checked... all pipework is connected fine

    We will see what LG say when they visit.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by Ross View Post
    I don't agree with what you suggest above........Think about another analogy. You take your car whether it's a Ford, Toyota, etc with what you believe to be an ongoing problem to the dealership. You know their workshop has available the computer software (which every car dealership has these days supplied by the manufacturer) to connect and the Technician turns to you and says I wouldn't bother with using it! Whether they find a fault or not I think for peace of mind for both the customer and the Technician it is necessary to use in a case such as this.
    I agree The control software should show what position the valves are at etc and what readings the thermisters are getting.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    UPDATE - LG Attended Yesterday:

    Very friendly and knowledgeable chap... arrived at 8am.

    The man connected a laptop, checked all sensors and found that 2 of the indoor units had loose connections on the board where the sensors connect. This could cause the unit to throw up an error code showing that the sensor was missing/shorted (never happened) or it would raise the resistance and give false readings back to the outdoor unit. He is to arrange replacement sensors to fix this.

    Checking over the outdoor unit all sensors were ok on here... the outdoor air temp sensor had a plastic sheath round it and he said this will cause the sensor to be out as the air wont get to it (I disagree it may slow down reaction time by a few mins, nowt major though). So he cut that back so the sensor itself was in the air directly. The laptop showed that valves were operating etc and nothing stood out as not working properly but what the laptop doesnt show is if a valve is stuck as the system doesnt have sensors to show that a valve isnt operating correctly. I queried this but he said that it would stick out like a sore thumb on the readings. (dont think it would if it was a fraction not closing properly) EG laptop would show valve at 30pulses but what if it was at 20 or 40 pulses this would let too much or too little through.

    He then did a calculation of the pipework and he says the unit is short of 220grams of gas. Strange as defrost cycles are few and far betweena and when it does the timed 5 hr oil return cycle there is never any ice built up on the outdoor unit. I queried if this would make much difference he was adament that it would cause an issue of poor heating. What I dont understand is that when the unit does a defrost or a oil return cycle and goes back into heating the heating performance and air offs are very good until the next cycle when they are back to being poor at 32C or so. Even putting it upto 30C they go up a by a few degrees but not much.

    As soon as I turn another unit on the performance is good, we get good air off temps.

    My engineer is going to come back and reclaim refrigerant through a drier and weigh it out to see whats in it as possibly short of refrigerant (why no freezing up of outdoor unit though?) if its short will need new refrigerant as I understand the gas is made up of different components.

    Is there any logic in this email I sent to him this morning: What do you think:

    "Very poor heating again this morning, only 32C air off in lounge (unit drawing 1.2kw), then the unit went into oil return mode (not defrost as its 6C outside and no frost on the coils) and 5 minutes later it is blowing air out at 40C and compressor drawing 1.6kw, is this a sign of it being undercharged such poor heating till it does oil return? Just funny how as soon as its done oil return I get good output. Also the fact that when two units are running means compressor is pumping harder to so if it is short of refrigerant how do I get better output when two are running as there is still the same amount of refrigerant isnít there."

    Let me know guys... hoping that it just a gas issue as its going to be an expensive winter when it gets really cold again (fan heaters etc)

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Hi Richard,

    Sounds like you are getting somewhere now. Even though 220grams may not sound like much from my experience it can make a difference. I would suggest adding it. Also I would suggest selecting the 'LONG' pipe setting on the outdoor PCB. It may help by ramping the compressor up a few extra Hz. Just remember it is more likely that a system will go into defrost more often in temp > 0 deg C as there is more moisture in the air than < 0 deg C. Also as oil return and defrost perform similar functions this should aid in ensuring the system runs at its optimum capacity at the duration of the 2 functions hence why you are getting better air 'OFF' temps.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    The long pipe setting is already in use, haven't noticed any difference in performance at all. The whole thing is very poor. The guy was telling me not to be concerned with air offs but my opinion is if they are poor then that's the reason for low heating capacity.

    Strange thing is when all 3 are running I am supposed to be getting less duty as the outdoor is over subscribed but I actually get better performance when all 3 are running than if just 1 is running which I am not supposed to get. So I would expect lower air offs when all three are running but no i get air offs of 47c versus 34c max when just one is running.

    Nothing matches up with the data book at all.

    Gonna be getting fan heaters out if this doesn't resolve it. I am hoping there isn't a leak, I noticed yesterday there was like an bluish film on top of the condensate that was coming out from under the unit. So hope the outdoor coil doesn't have a leak.

    To get the gas recovered, purged with nitrogen etc, recharged is gonna cost me another £300. Could have had mitsi put in for what this has cost me.

    Gutted

    Quote Originally Posted by Ross View Post
    Hi Richard,

    Sounds like you are getting somewhere now. Even though 220grams may not sound like much from my experience it can make a difference. I would suggest adding it. Also I would suggest selecting the 'LONG' pipe setting on the outdoor PCB. It may help by ramping the compressor up a few extra Hz. Just remember it is more likely that a system will go into defrost more often in temp > 0 deg C as there is more moisture in the air than < 0 deg C. Also as oil return and defrost perform similar functions this should aid in ensuring the system runs at its optimum capacity at the duration of the 2 functions hence why you are getting better air 'OFF' temps.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Any updates.....

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Paid £400 for reclaim, (no refrigerant loss whatsoever just slightly undercharged) so unit has exact refrirgerant weighed in as per LG.

    However issues are still exactly the same. No change so I am not very happy.

    WHen the system works it works very well however the next cycle on it may be very poor and air offs will be poor.

    FOr example the other day when it was -2C outside an hour before I was getting air offs of 41C then an hour later air offs were 28C with no change if I put the set point upto 30C.

    So I am back onto LG to see where they are going to take this next.

    I still think its the EEV's as the outdoor unit main header pipe has higher temps than what gets to the indoor units. So its almost like the EEV's are not allowing enough gas through.
    Last edited by back2space; 05-12-2010 at 12:39 AM.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    What's the refrigerant?
    Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by DTLarca View Post
    What's the refrigerant?
    Hi Mate

    Refrigerant is R410a.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    With hand held instruments or with the lg software, cable and dongle were the subcool and superheat readings taken during operation before a defrost and then later after a defrost?

    I'm just trying to work out where the refrigerant is during operation changes.

    If it was R407C then internal fractionation would be a possibility. But with R410A there would be zero fractionation problems.
    Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.

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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by DTLarca View Post
    With hand held instruments or with the lg software, cable and dongle were the subcool and superheat readings taken during operation before a defrost and then later after a defrost?

    I'm just trying to work out where the refrigerant is during operation changes.

    If it was R407C then internal fractionation would be a possibility. But with R410A there would be zero fractionation problems.
    Yes they were and LG said all readings came back ok.

    Thing is its not nessasarily after a defrost cycle this happens, could be the next on cycle that performance goes up or the next cycle performance may be poor.

    Usually always good performance after a defrost cycle though.

  50. #50
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    Re: LG Multisplit ongoing issue... slowly getting there I think!

    Quote Originally Posted by back2space View Post
    Yes they were and LG said all readings came back ok.

    Thing is its not nessasarily after a defrost cycle this happens, could be the next on cycle that performance goes up or the next cycle performance may be poor.

    Usually always good performance after a defrost cycle though.
    Need to check actual inverter frequency at the different times then.

    Most multi meters fail to register the hz coming off of inverters - instead we have to measure the volts onto the motor which increases with hz.

    Just to eliminate any chance of a discrepancy between intended frequency and actual frequency.
    Only the dogmatist says he will never change his mind. We all know that some of our opinions are wrong but none of us know which they are for if we did then they just wouldn't be our opinions. - JS Mill.

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