Fujitsu 8 yr old ABT24LBAJ indoor & AOT24LMADL fan light fault

[scottynz]

I posted this in the wrong section, sorry.
The indoor unit is model ABT24LBAJ and the outdoor unit is a model AOT24LMADL. The fault codes or flashing lights is 14 on the green timer. This says outdoor fan.

I have replaced outdoor fan and it still runs hot for 20 minutes to 2 days then faults 14 flashes saying outdoor fan.

I replaced with 7 second hand outdoor PCB and the same fault same problem. sometimes it would run for 10 minutes (outdoor temp about 3-5c) and other times it would run for 3 days (about 10c).

The ambient temperature outside is quite cool.

To top it off sometimes the indoor unit is blowing cold air. It's a floor mount.

Sometimes it runs hot then faults when it hits defrost and other times it goes to blowing cold air instead of hot on indoor unit.

Thanks for all your help.

Scott New Zealand, its now winter.

[scottynz]

Any ideas fellas and girls.

[nike123]

What about fan wiring? Did you checked that they are OK?

[install monkey]

4 way valve? dirty coil

[scottynz]

Yes I put another fan and tested 3 fans all the same on my multi-meter. Thank you for your thoughts.

[scottynz]

Thanks, the coil is clean, cleaned with coil cleaner.
4 way valve, now thats a part I have no idea about. is it easy to check or replace.
Thanks for your input.

[scottynz]

Anymore ideas??

[Tol]

Hi Scottynz. Check the outdoor coil sensor or outdoor air sensor. They could be faulty and telling the system to go into de-ice. You will need to get the resistances for these from Fujitsu. Cross reference the resistance against the ambient temperature.

[ozairman]

Sorry for the late reply, I don't come here very often and my memory on Fujitsu's is pretty rusty.
That model has an AC fan motor in the outdoor unit so no RPM feedback to trigger the error like with a DC fan motor. The triggering for the outdoor fan motor error is judged on the rate of change of the outdoor coil temperature sensor, versus the ambient air sensor. Apart from checking the sensor resistance temp specs I would consider reclaiming and weighing the charge to rule out if it's short of refrigerant, these things are charge critical and just fitting gauges is a waste of time.
It could also potentially be undersized and failing to recover normal operating temps after a defrost under cold ambients but that would have probably shown up before now.
Another thing to check would be the EEV coil in the outdoor unit, check the resistance fo the coils and also that it makes the right clicks and tick when it initialises on power up.
HTH