Monday, September 26, 2022


Quick RV Tech Tip: Furnace runs too long. What’s the problem?

Dear Dave,
Our furnace runs longer than it should. If it’s an air filter, where is it? — Joy H.

Dear Joy,
The furnace operation is controlled by the thermostat, which monitors the temperature and creates a closed condition that supplies the furnace control board with 12-volt power. If you set the temperature at 70 degrees, once the inside temp drops below that temperature +/- 5 degrees, it sends 12-volt power to the module board and the motor/fan starts until it raises the sail switch and then the gas valve opens and it lights the burner assembly. When the temperature gets to 70 +/- 2 degrees it shuts off.

I would suggest getting a thermometer and verifying what the temperature is at the thermostat. This will tell you if the furnace is actually performing as designed or really is running too long.



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dale p
1 month ago

And why not give reason of why this would happen ?
Example High Temperature sensor bad. Bad connection of said sensor to shield.

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