Short Cycling AC

[Latitude]

One of my roof top AC units after it reaches the set temp will short cycle. Every 3 min or so it will run for about 20-30 sec.

Any ideas???

Rick

[Latitude]

One of my roof top AC units after it reaches the set temp will short cycle. Every 3 min or so it will run for about 20-30 sec.

Any ideas???

Rick

[RV Wizard]

You may have a vent dumping air directly onto a temperature sensor (thermistor).

[GaryKD]

Hi Rick,
Welcome to the club on this problem. I had the same thing happen to me. The solution, that worked for me, was to install a new thermistor. The original thermistor was left in place, but disconnected at the roof A/C.

The new thermistor wire was run from the roof A/C through the air return duct (this is important, not the air delivery duct, but the air return duct) into the rear bedroom. I tried many locations for the thermistor. For me, the best location was just inside the air return grill. I placed the thermistor in a plastic sheath (wrap) and taped it to the hidden part of the grill. The excess wire is laying in the air return duct.

[OpaRon]

I'm a little late coming to this thread, but we just left Camp Newmar with that exact problem. Our rear heat pump did the same thing - 30-40 seconds on, 4 minutes off then the same thing - except mine only blew cold air. The problem was in the EMS! Had to replace a board in it's brain - no more problems. Works great, even down to 36 degrees. Working well here at Camp Spartan. Dennis was our Newmar tech and figured it out.