Problem with Day & Night Forced Air Unit - http://www.hvacmechanic.com/ Forums
Original message
Paul S
"Problem with Day & Night Forced Air Unit"
, posted Mon 24 Oct 17:25
I have a Day & Night forced air unit (model no. 125CU-12A). When the thermostat calls for heat the pilot lights the main burner and when it is upto temperature the blower comes on and everything continues to operate properly. Then, in the middle of the heating cycle the main burn goes out and then comes right back on and then goes out again over and over. I found that if I use the gas flow control atop the regulator to reduce the flow of gas to the main burner I can delay this but if the furnace remains on long enough it will start to go out and come back on again repeatedly. I thought the problem might be related to the temperature sensor in the bonnet so I jumpered it out of the control circuit but the problem persisted unchanged. Since everything functions properly for a good while after the furnace initially comes on its hard to figure out what's failing, any suggestions?
"Problem with Day & Night Forced Air Unit" 
