My gas furnace won't fire up. It triggers the induced draft motor, which runs for about 20-30 seconds, and then the whole system shuts down. Up until yesterday it was working fine and I had been running it for a couple weeks now (in Minnesota). The only thing that changed was that yesterday I was going round the house and sealing up all the penetrations, and I blew some Great Stuff around the exhaust vent. I've checked the vent and no foam got in the pipe/vent, and none even came through to the inside side of the joists. It all just went behind the vinyl receptacle cover and AROUND the vent.
There is a little condensation around the inside of the pvc pipe, but I'm not sure if this is increased from before I added the Great Stuff (I never looked that closely before).
This is a horizontal concentric termination. I'm getting error code "45"which is : low pressure switch is open. Possible issues:
-insufficient combustion airflow
-insufficient combustion air
-improper pressure switch setting
I'm not sure how adding spray foam AROUND the exhaust changed anything. Other that scraping out all the spray foam, is there something else I should correct or look at?
Can you guys help a single girl out??Thank you very much!