โNov-03-2022 12:58 PM
โNov-05-2022 07:48 AM
John Burke wrote:
Make sure your thermostat is set to auto, not heat. If not the heat strip in the A/C unit will be the first to come on. The heat stripe will heat, and the furnace fan will run.
โNov-05-2022 07:47 AM
wnjj wrote:
If it were me, I'd disconnect the thermostat and directly connect the heat(W) and +12V(R) wires. If everything is good let the heater run for a few minutes then disconnect, wait a few minutes and repeat.
If that is all good, replace the thermostat. It's nothing more than a relay that shorts those two wires when heat is desired.
โNov-05-2022 05:53 AM
โNov-04-2022 05:20 PM
โNov-04-2022 08:38 AM
โNov-04-2022 08:31 AM
โNov-04-2022 07:45 AM
wnjj wrote:dougrainer wrote:
You have a bad FURNCE ignition module. Once the furnace blower comes on, the AC and Wall tstat are out of the picture for ignition control. This type failure is common for a bad Furnace Ignition module. It is VERY hard to diagnose. This is where years of knowledge comes in. Doug
Except the OP said when they turn the temperature up one more degree on the thermostat, it lights off. I would think a bad ignition control would stay bad under that circumstance. Maybe the thermostat is bad and only pulses the heat wire briefly which causes the fan to start up but not light off?
โNov-03-2022 10:47 PM
dougrainer wrote:
You have a bad FURNCE ignition module. Once the furnace blower comes on, the AC and Wall tstat are out of the picture for ignition control. This type failure is common for a bad Furnace Ignition module. It is VERY hard to diagnose. This is where years of knowledge comes in. Doug
โNov-03-2022 06:58 PM