Jframpey wrote:
How long are you waiting to reset the thermostat? The fan is designed to run for a minute or two after the furnace turns off... To cool down the combustion chamber.
This!
The fan runs for about 90 seconds on mine after the flame shuts off but since the heat exchanger is still hot it keeps putting out heat and ends up going over the set-point.
The solution is and Energy Star rated stat (the Hunter is an improvement but not as good as an ES stat). An Energy star stat uses a processor to calculate this temp overshoot and will actually shut the furnace down prematurely to keep over shoot from occurring.
Mine would over shoot by about 3 degrees. The Hunter stat brought that down to about 2 degrees and the ES rated stat hit's the temperature setting dead on every time. They are more expensive but worth it if overhsoot is an issue - and it will save gas and battery power.
