Comfortmaker RPJ2

rusty55125

I continue to have problems with my Comfortmaker RPJ2 furnace and it getting worse. This is what it's doing. When the temperature on the thermostat is set below the room temperature, the exaust blower cycles on and off. It's been taking less time before between the cycles, it used to take a couple of hours after the the thermostat stoped calling for heat to start this cycle but reciently it happens just after the furnace shuts down. The thermostat is not calling for heat while the blower cycles. When the temperature on the thermostat is raise so it calls for heat the furnace works normally. Once the thermstat doesn't call for heat, the blower motor starts cycling, just enought to get the motor upto speed and then shuts off then restarts, ect. This continues until the thermostat calls for heat again. I have repaced the thermostat but nothing. One other things is, while it's cycling, if I turn off the thermostat, the cycling stops.
Any help out there??

Aceinstaller

too many things to list.

probably miswired or a bad board.

call a service tech.

rusty55125

I, over the weekend added a simple mercury switch thermostat. This is as simple as you can get type. This one is working just fine, when I turn the temp down the furnace stays off until the time is reached and then runs normally. Can there be something wrong with the thermostat model I was using. The two thermostats are running the same and look like the same model, just a few years apart in manufacture. They were the Honeywell adjustable thermostat with a four setting weekday and two setting weekend settings. When I put these into the system they perform the same as previous post. The simple thermostat works fine but I do what to go back to the adjustable ones, is there anything I should look for?

Aceinstaller

sometimes t-stats will go bad.

sometimes, there is improper low voltage to the stat.

sometimes the factory will ship a bad t-stat.

just try a new one, but make sure to connect the proper terminals as directed in the instructions.

Hogan's Hero

Check thr flame sensor....