Daikin heat pump advise needed.

[Essex1968]

Hi

I posted on here some time ago about a system i was having installed

http://www.refrigeration-engineer.com/forums/showthread.php?15885-ashp-as-primary-heating-source&highlight=ashp

Everything seemed to be fine apart from a slight problem with one FDXS50C unit. I called the installers back a few times but each time they assured me things were ok. I'm still convinced there's a problem.

In heat mode the system starts up fine and begins to heat the room. After a while the performance drops off until it's only delivering a mildly warm air. The unit then goes off and wont come back on again even if I increase the temp setting. When I switch on the other FDXS50C that shares the same outdoor unit then it starts back up and again delivers warm air. I've tried changing the room sensor but the problem persists. I'm sure that the air isn't short circuiting in the room. This occurs with all outside temperatures. I'm not getting any error codes. Any suggestions what might be the problem please ?

[install monkey]

have a read through this
https://rapidshare.com/files/2759046207/SiBE18-621_tcm219-61312-fdxs50.pdf;

[Essex1968]

Thanks. I was left with an operating manual for the units which i've looked through. The troubleshooting section hasn't been too helpful. I've just run a 30 minute test that has proved inconclusive. Any other suggestions would be appreciated before I turn to a random engineer from yellow pages.

[install monkey]

hold the cancel button for 10 seconds,keep pressing and u get short beeps,wait till the long beep and thats ur fault code-u may have to wait till the unit fails though- its common for lev's to fail so limiting the output

Thanks. I was left with an operating manual for the units which i've looked through. The troubleshooting section hasn't been too helpful. I've just run a 30 minute test that has proved inconclusive. Any other suggestions would be appreciated before I turn to a random engineer from yellow pages.

[back2space]

Does the system operate properly if both your indoor units are turned on and calling for heat? Or is it when only one of the units is calling for heat and the other is at thermostat off that you see performance drop off?

Does the same occur on the other unit?

[Essex1968]

Thanks for your replies. I'm not actually getting a fault ( green flashing LED ) I've tried runing through the fault codes but can't detect the problem.

Yes, if both indoor units are on and calling for heat then the unit performs fine. Its only when it's operating alone that I have the problem. I've not tried running the other unit alone yet as I very rarely use that room. I'm running it solo at the moment and will post my findings later. Thanks again.

[Essex1968]

The performance of the other unit also drops off when it's runningn solo and only when I activate it's paired unit does it begin to operate ok. Does this point to a particular fault with the outdoor unit ?

[back2space]

The performance of the other unit also drops off when it's runningn solo and only when I activate it's paired unit does it begin to operate ok. Does this point to a particular fault with the outdoor unit ?

How do the units perform if you only have ONE unit physically switched on? Ok I bet.

My LG units which are also multi units on one outdoor unit perform very poorly when in heat mode if only one indoor unit is calling for heat and the others are in standby (thermostat off but still turned on) this is because the fans periodically run to clear heat from the coils of the units that are thermostat off removing heat from the system so the room still calling for heat takes for ever to heat up. THis is on the floor mount units though and the wall mount unit doesnt run the fan at thermostat off no matter what so perofrmance of the other units is not affected.

My resolution to this as LG did not want to know about their design fault is to get each room upto temperature individually by running only one unit and then when that room is upto temperature i.e 22C I then turn the bedroom unit on and that is only maintained at 18C so reaches temperature ok and then the lounge will maintain 22C.

Do the fan continue to run on the other unit when they have reached temperature?

[Essex1968]

When running either of these 2 indoor units alone then the performance is poor. Its worth pointing out I have 6 other indoor units that all work perfectly fine when running independently. On the troublesome units the room may not even get to temperature before the air delivery cools and the fan may switch off or may continue running but with no or very low heat.

[back2space]

Yes but are you running these 2 together or is only 1 of them switched on when you have poor performance.

[install monkey]

green flashing light is communication between indoor/outdoor boards

Thanks for your replies. I'm not actually getting a fault ( green flashing LED ) I've tried runing through the fault codes but can't detect the problem.

Yes, if both indoor units are on and calling for heat then the unit performs fine. Its only when it's operating alone that I have the problem. I've not tried running the other unit alone yet as I very rarely use that room. I'm running it solo at the moment and will post my findings later. Thanks again.

[Essex1968]

only 1 is on when performance is poor.

[r.bartlett]

Gas charge needs to be proved correct

[Aircon467]

has this problem been fixed?
few questions for you if not?
is this a ducted / void unit?
where is the return air sensor fitted/located
is the return air from the room in question ducted to this unit?
what is the distance between the return air and supply air grille?
do you have an infa red remote controll or hard wire wall mounted remote controll?
what is the supply air temp @ the supply grille? (after 15min)
what is the return air temp @ the return air grille? before & after 15 min)

[skags]

Have they checked the interconnect wiring is going to the correct indoor unit, If you put one on heating and leave the other off does the coil temp or pipes get very hot on the other unit that is switched off,... Im not familiar with those particular models but you could try putting one on fan only and they other on full heat and see if the fan only one gets 40+ degC Supply air , If so then high possibility The interconnect wiring needs to be swapped buy the installer,..