please help

[marc5180]

Hi Guys sorry for the double post this is my first post on here and im looking for a bit of help, i was called on a routine maintenance visit to a college today that had an LG twin unit ( 1 condenson attatched to 2 cassettes) in one of the class rooms. One of the cassettes seemed to be working fine but the other one was flashing up a fault code "04" i thought it would be the tray blocked in the cassette so i went ahead and removed the tray. When i removed the tray it wasnt dirty at all. I tried to get the lift pump to work by pushing the float switch but nothing happened. Out of interest how would i check wether it is the lift pump or the float switch that needs replacing. How would i check if it was open circuit? I know this may be too easy for most of you guys but its only easy if you know it. Also when i cleaned out the tray and put the cassette back together i checked to see what the cooling conditions were of the cassette and i was getting 21 degrees air off and the ambient of the room was 22. I went on the roof and checked the condensor but on system A the charge was ok but when i put my guages on system 2 there was no refrigerant in it. So my question is do i recover the gas just from system B? Are the twins 2 seperate systems inside 1 condensor or are they 1 system and i have to recover all ov the refigerant from both systems?
Please help

[davej]

hi mark ,the fault codes are normally on the drop down flap of the hard wired remote, and the systems are normally separate circuits. try turning off the mains and restarting after you have repaire the gas leak as it has probably locked out on low pressure

[marc5180]

Thanks for your reply, do you know a number that i can get technical help from LG as im going to need to know the charge that i will have to weigh in and there is no info on the condensor

[Temprite]

G'day marc

From what I know about these units drain pump should have power to it at all times when the unit is running on cooling.

Switch unit on cooling and check at indoor board connecter that pump is being supplied with said voltage.

As far as the gas charge goes seems strange that nameplate charge is not supplied on the side of the condensing unit.

[marc5180]

how would i check wether it is the lift pump or the float switch that needs replacing. How would i check if it was open circuit?

[marc5180]

how would i check wether it is the lift pump or the float switch that needs replacing. How would i check if it was open circuit?

[eggs]

what you have to do is drop the drain pan, as there is no other access on these piles of sh1t, but before you do that you have to disconnect all the wires of the indoor board.
So now you have access to the float switch and drain pump but no power
Anyway, after you rig up some power and test the pump and float switch, you will find both of them work and you are back to square one

THE INFAMOUS UNEXPLAINED LG WATER LEAK.

if it is the pump by any chance, i have a perfect working one i got as an advanced warrenty replacement, but couldn't be bothered sending back. Im in Lancashire myself, you can have it if you need it and save yourself £75.00.
I solved the problem by ripping it out and fitting somr trouble free Hitachi.

cheers

eggs

[marc5180]

thanks for the offer im going back there tomorrow so il let you know. I did what you said i disconnected the electrics and dropped the tray then put the power back on but the lift pump wouldnt work... how do i know if its the pump its self or the float switch. How do i test if the float switch is open circuit iv done this before but forgot?

[marc5180]

Also when im taking the gas out of system A is there no way that when im vaccing out system A i wont be breaking into system B at all, i mean can i leave the refrigerant that is in system B in there while i pressure test and vac out system A? Please reply as im doing the job in the morning

[eggs]

the float switch is just a magnetic contact type thing, so it's a normally open circuit. as you lift up the polystyrene float by hand you will hear a relay on the board click and the motor start to spin.
or put your multimeter on .............etc.... etc...

[eggs]

Also when im taking the gas out of system A is there no way that when im vaccing out system A i wont be breaking into system B at all, i mean can i leave the refrigerant that is in system B in there while i pressure test and vac out system A? Please reply as im doing the job in the morning

yes, they are seperate circuits. circuit "B" will be fine left alone.

cheers

eggs

[Temprite]

Correct me if I'm wrong.

Last time i worked on an LG cassette I am sure that LG stated that condensate pump is energised any time the unit is on cooling and float switch is for high water level alarm only.

Different models may differ.

[aeb200]

yes temprite is right!!

the float switch is a safety for high water level - this is what gave you the CH04 fault code in the first place!!!!!

the pump will run continuously when unit is in cooling, the easiest way to check the pump is spray water onto coil (using a garden sprayer with lance attachment) through the louvers (make sure unit is off or you'll blow water into room). then turn unit on in full cooling and check drain outlet-there should be a small trickle. also you can turn cooling and fan off and you should be able to hear a hum as pump runs (for 3 mins after cooling cycle finished)

the ch04 fault may have been generated if machine was short of gas - coil ices up then defrosts causing drain pan to overfill with water

hope this helps
aeb200

[captain cook]

bloody hell is this the way it works in the old country, throw a guy in at the deep end and stand back.

[Andy W]

do you know a number that i can get technical help from LG

Save your breath, they know less than us. Identify and repair the gas leak first, once running and charged with gas then test the pump or you will be looking for problems which don't exist, or in LG's case, there are lots of problems you have not yet discovered.

[old time fridgy]

hi, i think all your questions have been answered but just wanted to add that i have been to loads (11) of those LG (commonly known as Looks Good dont work though) twin or multi systems all with internal leaks in the condensing unit usually discharge pipe or on bottom of condensor but they assure us THIERS NOT A PROBLEM WITH OUR KIT IT MUST BE THE INSTALLERS but why then have they have taken on extra technical staff to cope with thier NOT A PROBLEM KIT. it may be cheaper to buy but it costs you more in the long run. been caught out a few times with going back to site to rectify MY INSTALLATION PROBLEMS internally on thier units, but not anymore.

[aeb200]

LG (commonly known as Looks Good dont work though) .

We call them Low Grade

[Temprite]

I thought it was Lousy Goods.

[eggs]

no it's "L"eave alone and fit some "G"ood stuff like Hitachi or Daikin.