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View Full Version : fujitsu high discharge on heat mode.



savoc
18-08-2011, 07:01 AM
Hi guys i place this message in the wrong forum before. i hope can get some help here. having trouble with a ducted fujitsu r22 aot?. when i got to site the a/c had just been started in heat. i found the hot gas line going to the indoor unit to be very hot (a/c cut out on high discharge temp)and the return liquid line to full frosted it looked like liquid coming back. i assumed the a/c was low on gas. ran the unit on test mode cooling. i then had very high suction pressure for a cold day around 580kpa (not low on gas). i checked the reversing valve, i used a magnet on the valve to check the operation and touch tested the pipes, feels ok. Put the a/c back into heat mode and it ran fine. discharge line was touchable and the return line was warm. house got warm straight away. Air filter was trashed i removed it, carried out compressor capacity test all okay. a/c ran fine for 2 nights now playing up again. i think the electronic tx is ok. I belive it may be the reversing valve, what are the correct test for a valve? the customer also said this is the first time its played so no one has ever touched the gas charge. Any glues? dirty indoor coil? faulty valves? any other fujitsu tests?

paul_h
19-08-2011, 05:49 PM
check ducting, could be collapsed. Check indoor coil, could be full of dirt. Also fan motor or cap could be dying, or zone motors shutting.
You need pipe temps across the r/v valve inlets and outlets, and air temps on and off coils. Also pipe temps across any possible restriction (tx, driers, accumulators, service valves, coil inlets and outlets etc )