Wallmount error,any help welcome!

[Danny11]

Hi guys

I was on a job the other day,A Fujitsu (asya24lcc) which is a small wall mounted inverter split.
I was getting a OF error code which is a discharge fault.So i checked the pressure of the system and it was low on refrigerant.
I Reclaimed,Pressure tested and re-gased and all is ok.
BUT.....On cooling its fine as it pulling on air 11c. But on heating it decide to not work at all.The louvers stick to a down point and fan dose'nt run.

Im a approved fuji engineer but this is a mine boggler.
Is there any experts owt there because clearly im not.

Cheers guys:confused:

[p_p]

Hi Danny


I take it that the outdoor unit wont run in heating mode ?




PP

[sinewave]

Two possibilities I'd say..

PCB fault in the indoor unit?


Faulty reversing valve?

[frank]

I'm not fully upto date with the control logic on this model but, if a system runs Ok in cooling but hangs in heating, it's normally because the software if asking the compressor to run then waiting for a set increase in indoor coil temp before it allows the indoor fan to run. This is to stop cold draughts in heating mode.

Possible causes are:

Indoor coil sensor out of the pocket
Indoor coil sensor U/S (out of calibration)
Lack of refrigerant
Faulty 4 way valve
PCB fault

As your model sets the louvre position for heating but the fan doesn't run it is probably one of the above.

Let us know what you find.

[Jase]

There may be a faulty thermistor on the outdoor unit which in turn could possibly be causing the unit not to operate in heat mode.

Jase

[anuraruna@gmail]

Fan has to run .May be a card fault or thermistor faulty.Easy to check thermistor. Remove thermistor cables and replace by hanging a new thermistor or known resistor.and try to start.

[paul_h]

Hi guys

I was on a job the other day,A Fujitsu (asya24lcc) which is a small wall mounted inverter split.
I was getting a OF error code which is a discharge fault.
What's this fault code?
Here all the wall splits just flash LEDs at you and there's nowhere to read a fault code :confused:
Is there any flashing LEDs on the indoor unit, like the operation light or the timer light, if so how amny times each?


edit: also it sounds like the indoor fan isn't running because the coil isn't hot (or is the coil hot but no airflow?)
Is the compressor running when it's doing this? what are the pressures and pipe temps?

Check the reversing valve, make sure you have voltage to the valve solenoid plug, test the solenoid coil to see if it's open circuit.
If there's power going to a good solenoid coil, and the compressor is running but there's no HP at the suction service valve (ie the service valve is cold and at LP), it looks like the reversing valve is seized.

How old is the unit, it's pretty rare for a system that's been working on heat before to suddenly seize up the valve.
aslo make sure the TX is mounted properly on the pipe and hammers open and closed normally at system power up.

[coolments]

Hi danny

It seems that we can all agree the unit is stuck in pre heat mode, You say OF fault which is discharge related, i assume this is abnormal temperature reading (high) not that familiar with fuji stuff.

The gas you have checked as correct, so I would be diverting my attention to the indoor coil sensor, if it is corrupt it would not read that the coil is up to temperature and keep the unit in pre-heat mode, this would eventually cause an abnormal discharge temperature as the pressure rises in the circuit.

Hope my suggestion helps