Today I tackled the furnace problem I've had since I left Arizona. The Suburban furnace is pretty easy to remove for service. Just take off the front plate...two screws, then remove the ductwork and disconnect the propane line. Two more screws and the power plug and out she comes.
A while ago I had the furnace outside vent covered to keep out bees...and for some reason I was working in the trailer and wanted heat. I turned on the furnace forgetting about the plastic cover on the vent. The furnace ran for a bit, as it always does to purge the system and then ..."BOOM"... and I realized instantly what I had done. I ran outside thinking I might find a new storage locker...no damage that I could see, and the furnace worked okay. Thinking I got away with it, I was pretty happy.
We went to Arizona, it worked all winter, perfectly. When I left Arizona for home, the first night it didn't work. It would start, run for twenty five seconds, and shut off. This likely meant that the purging air was not flowing and the sail switch was not allowing the gas to flow.
The furnace has to come out of the sheet metal box it lives in, for service. I did this, with some struggle. Immediately I could see that the cover over the purge fan, not to be confused with the fan that moves the heat into the rig, was shattered into a few pieces and was partially in place but coming apart. It's quite amazing that it worked all winter. Without a tight fit, the air escapes from the purge fan space and therefore does not purge the burner, and does not move the sail switch to allow gas to enter the burner.
There was a person recently who had the same symptoms as I did with the furnace running a few seconds and then shutting off. This may be why it's doing that.
I didn't get away scott free with covering the vent with plastic after all...
$35.00 for a new fan cover....not bad for being stupid, huh???
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