I recently changed from a manual-digital thermostat to a Lux TX9000TS electronic thermostat. All functions (Air, Heat & Fan) worked with the old thermostat. With the TX9000TS the air works fine and the fan blows in fan only mode. In the heat mode the Gibson air handler in the basement clicks and sounds like it's going to come on. There is fire in the burner and after a time the fire kicks off... I assume a safety feature because the blower does not come. I have read the manual and double-checked all wires. The heater jumper is in as indicated in the instructions. This is actually the second time this has happened. Last winter I purchased a Hunter programmable thermostat and it did the same thing. At the time, I thought it was a faulty thermostat and I re-installed my cheap stock thermostat. Any ideas on what may be the matter?

Any help is appreciated.

Thanks,

Brian

1st thing,, assuming whoever ran stat wire have red as hot, white for heat,, tie the 2 together,and see if furnace goes into full operation, keep in mind this is bypassing the thermostat,, are you still having prob. With the fan not coming on and the fire going out because the fan not working, if all works well this would send you in direction of problems with the stat

Modern furnaces have the blower controlled by a timer on the control board in heating mode. Older ones it is a limit switch in the furnace. Usually the heating blower uses a different motor winding an relay than the cooling and fan on. Sometimes you can get the furnace to run using the fan on position. See the sequence of operations for a gas furnace in the sticky at the top of the heating forum.