DuoTherm Relay Clicks rapidly, then changes to Heat Pump

[sknopster]

My DuoTherm Penguin 630515.321 is the front A/C of 3 total. When running this unit either alone, or same time with another one (or two) and while plugged into 50 amp circuit on my own site (as well as other sites and when using the Generator), this unit will eventually start making an easily heard "clicking sound". It sounds like a relay throwing, quite rapidly and with no precise timing. It can happen after the first 3-5 minutes of starting, or after running for several hours... but eventually it always displays this symptom. And it ALWAYS ends up pumping out HOT air. This makes me think it is changing to the Heat Pump mode.

I have swapped the DuoTherm Comfort Control Thermostat with no change. I've read that it is important to have all thermostats set to the same mode... "Cool", so I make certain that BOTH stats are set the same. I have also tried just leaving the other stat turned off. I have tried cutting the breakers for Both of the other units.

Has anyone experienced this? Does anyone have an idea where to begin? Before I start taking things apart, I would like to have a plan! I'm thinking it wouldn't hurt to clean the heat exchanger, check all connections and perform usual maint. Btw, when it's cooling, it blows 55 degree air on a 80+ degree day. Also, my parents owned this coach for the first 8 years of it's life. 2004 Monaco Dynasty, Regal 42'. I noticed that the A/C's only had a thin foam intake filter, I have since changed them to 3M Filtrete 14" X 14" electrostatic filters. Makes me think I'm going to find a lot of dirt on the heat exchanger.

Thanks in advance.

Scott

[RV Wizard]

Check the control board terminals feeding the reversing valve and the reversing valve coil for loose or corroded connections. You can download the service manual from this catagory iRV2 Forums - Files - Heating and Cooling in our "Files" section of the forum. Good luck and keep us posted.