[left]So for the past three day I’ve been having trouble with my flame sensor. Off and on when the thermostat would call for heat, the inducer would start, followed by the other steps. After there was a flame though, it would kick off sporadically. Sometimes after 5 secs, sometimes after 2 hours. I cleaned the sensor and for 24hrs it ran normally. Came home from work to find furnace off with nothing running at all. Now I have a rapid flashing light which apparently means reversed polarity. Any help at all would be appreciated. [/left]

Hello I have a Bryant furnace with a hot surface ignitor. A few days ago or so, the thermostat would call for heat (and click) and then the furnace would start but would shut down a short while after (~30 sec - 1 min). I checked the LED codes and it was a 14 code followed by a 34 code. 14 code is listed as "[color=#383a3b]ignition lockout" and refers to code 34 which is "ignition proving failure". After resetting (power off/on the unit) once or twice the system worked and I got heat. Now it fails ~1 out of 5 times with the same sequence of codes. I unplugged and cleaned the ignitor and it seems to be better. I ordered a replacement one just in case and I just measured the resistance across both of them - the new one is 55 Ohm; the old one is 75 Ohm. From what I'm reading the failure mode would mean it would need to be >200 Ohm to consider it 'fail'. Any other thoughts on what to check next? Thank you all![/color]