Confoozled
New Member
Hi all - my upstairs gas furnace will click to system "on" once the temp goes below set point, but it doesn't actually kick on. It will sit there as the temperature continues dropping showing "on" at the thermostat.
No fault codes in the LED window - light is steady on.
Some background - thermostat is a 6 month old Honeywell 7-day which replaced the original 20 year old Honeywell which was having trouble detecting battery.
I did some routine checking of the thermostat. For example with fan set to run, the blower runs fine. I also flipped it over to AC for a few minutes and the blower and compressor both run.
About 3 weeks ago I replaced the igniter because I had the typical symptoms of having a small crack - one time it'd run fine, the next time it'd kick to heat "on" and blower would run 20 seconds then shut down, indicating the igniter wasn't pulling enough amps to open the gas flow. Then next time it'd run fine again, but then the time after that do the short blower run and shutdown again. So I replaced the igniter. Both the old igniter (about 12 years old) and new one were Emerson 767a-370.
After I replaced the igniter it ran fine for about 2.5 weeks, but now, like I mentioned above, it says heat system is "on" but just doesn't want to run at all.
Thoughts on this? I don't think it's the thermostat given it works on fan and AC mode, but I've been fooled before.
And I'd think it's not the new igniter since it worked fine for a while, and is not now giving the "sometimes works sometimes doesn't" behavior I'd seen before. Instead indicates system on but doesn't do anything. But I've been fooled there before, too.
Many thanks!
No fault codes in the LED window - light is steady on.
Some background - thermostat is a 6 month old Honeywell 7-day which replaced the original 20 year old Honeywell which was having trouble detecting battery.
I did some routine checking of the thermostat. For example with fan set to run, the blower runs fine. I also flipped it over to AC for a few minutes and the blower and compressor both run.
About 3 weeks ago I replaced the igniter because I had the typical symptoms of having a small crack - one time it'd run fine, the next time it'd kick to heat "on" and blower would run 20 seconds then shut down, indicating the igniter wasn't pulling enough amps to open the gas flow. Then next time it'd run fine again, but then the time after that do the short blower run and shutdown again. So I replaced the igniter. Both the old igniter (about 12 years old) and new one were Emerson 767a-370.
After I replaced the igniter it ran fine for about 2.5 weeks, but now, like I mentioned above, it says heat system is "on" but just doesn't want to run at all.
Thoughts on this? I don't think it's the thermostat given it works on fan and AC mode, but I've been fooled before.
And I'd think it's not the new igniter since it worked fine for a while, and is not now giving the "sometimes works sometimes doesn't" behavior I'd seen before. Instead indicates system on but doesn't do anything. But I've been fooled there before, too.
Many thanks!