No HEAT or AC. Please help.

[michels280]

I have a 2004 3100se Maxum - 5k GenSet, Dometic Marine Air Systems heat/AC unit. I think its a 16000BTU. I was getting ready to winterize the heat / AC system, when I turned it on. Unfortunatly, the unit did not engage. The digital control worked fine, and the fan kicked on, but the comprossor / water pump would not active. The AC light stayed lit, even when I turned the temp up to 85. With it not kicking on, I could not run antifreeze through it to winterize.
I then did the factory automated self test, by holding the power button right when I hit the breaker. This did kick it on. I was then able to run antifreeze through it to get it winterized.
When spring comes around, this is the first thing on my agenda to fix. Any thoughts as to why it would not kick on normally, heat or AC, but would with the self test? it was 66 degrees in the cabin, 80 on the top deck (campertop up) 55 outside with the a 10 knot wind. Water temp was between 50-60 degrees.
Thanks in advance for your help!!!

[GordMay]

Greetings and welcome aboard the CF, michels280.

[mayball]

Hi michels280,
I have no experience with a Marine Air Chiller system, but most such systems have a low pressure cut-out switch in the refrigerant system that will not allow the compressor and sea water pump to run when a R-22 refrigerant leak lowers the suction pressure to about 38 psig. If it cuts out, the unit will not start until the pressure raises to 68 psig. This would be the case whether operating as an air conditioner or a heat pump It looks to me that you have a leak.

[michels280]

Thanks. I'll check the pressure.