Furnace Thermostat cycling

[Lumatic]

I have a newER NT30 in my older 71. The thermostat is original 71. The thermostat cycles the furnace too quickly when the coach is around room temperature. The furnace comes on fires for a short period of time, shuts down, the furnace comes on fires for a short period of time, shuts down, and continues annoyingly on this short cycle. I suspect the problem is in the thermostat. Can the old 71 thermostat be adjusted or should I chuck it out the window and put in a new one?

[azflycaster]

The thermostat in my 75 is a simple bi-metallic strip with a set of contacts which either are open or closed. When the trailer reaches the set temperature the contacts open, but the furnace continues to run for several more minutes. The additional run time is a function of the furnace not the thermostat. You can pull the cover off and watch the contacts make and break.

[markdoane]

I would try a new thermostat. Here's one that has the features you need, and it's cheap.

The heat anticipator setting will adjust the cycle time. You also need to check the location of the thermostat relative to the furnace outlets. If hot air is blowing directly toward the thermostat it will cycle on and off frequently. Sometimes adding an air deflector or adjusting a heat register away from the thermostat will help.