Propane direct vent shop heater

[varmint]

I have a small wall mounted direct vent propane heater, about 5-6 years old, that was working fine every winter until now. I usually have to clean the pilot thermocouple tip, but that's it. But now, the main burner flame is nice and blue close to the entry end, but mostly yellow at the far end. It shuts down after a heat cycle roughly, usually extinguishing the pilot. I relight it, and it may work okay for a day or so, but then shuts off on it own. I can't really access the main burner tube without a major teardown, and I don't have replacement gaskets... Gas pressure is fine- about 11 inches water column.

 

[kenmac]

I have a small wall mounted direct vent propane heater, about 5-6 years old, that was working fine every winter until now. I usually have to clean the pilot thermocouple tip, but that's it. But now, the main burner flame is nice and blue close to the entry end, but mostly yellow at the far end. It shuts down after a heat cycle roughly, usually extinguishing the pilot. I relight it, and it may work okay for a day or so, but then shuts off on it own. I can't really access the main burner tube without a major teardown, and I don't have replacement gaskets... Gas pressure is fine- about 11 inches water column.

there may be some dust clogging up the burner venturi . Blow out with air. Propane usually burns more yellow than does NG though .
Just replace the thermocouple if you have no way to check millivolts in circuit, or out of circuit . You may also need to clean the pilot as you may have dust in the pilot assy. as well.

 

[Roadworthy]

In addition to dust you could have spider webs in some of the small passages. That's a common issue with propane barbecues.