I have a FT 100 heater that the ignition (spark) doesn't seem to be working. The fan turns on for the draft inducer and gas valve opens for about 20 sec the shuts off then the gas valve comes on and off again 3 times the whole system shuts off. I don't hear the snap of the ignition like I use to. I tested the board power and it has 26volts supplied. Do you think the Ignition control bard has to be replaced? The part # XXXXX the board is 174260
UPDATE-6Dec2013-13:17: I just checked and the house is currently 67F and outside is -13F.
We've had a problem with our Trane furnace when it gets really cold since we replaced our old Furnaceman furnace several years ago. The Furnaceman heated like a damn, but we had some government incentives to go high efficient so we did it. The problem only happens when it's especially cold out, and since we installed our A/C we have also noticed the same problem with cooling. Especially cold means -25C or more. The interesting thing is that at the -25C to -40C range (-13F to -40F) the warmest temperature slowly lowers (depending on the outside temperature), but holds steady at a new "high point" for each level colder outside. For example, if it's -25C outside, it might max out at 21C or 71F. Today it is -30C outside and the inside temperature will go no higher than 20C or 69F. Certainly a thermodynamics deal, but the important thing is the furnace is not operating properly to deal with the temperature difference. The thermostat is a White-Rodgers Type No: 1F95-1277. Here is a link to the wiring plate as installed in our house. https://dl.dropboxusercontent.com/u/50236918/pics/DSC_0102.JPG The furnace is a Trane XV95, Model#: TUH2C100A9V4VAA, Serial#: 751536H7G. My wife has noticed that the temperature will go higher in Stage +1 and actually get lower in Stage +2.