Wrong Vent Cap can cause gas fireplace problems

[gjacquin]

Just a post to share information. My gas fireplace recently had issues - it would start up, but then go out and beep. I spent quite a bit of time messing with it, cleaning the pilot tube and flame sensor, replacing parts ... nothing solved the problem. Turns out roofers had put a new vent cap on, and it was different than what was called for in the installation manual. The roofing company made it right - they came back out and installed the correct cap - and now it works fine.

So beware that the vent cap can cause an otherwise perfectly working gas fireplace to malfunction.

 

[DAKSY]

Not sure what unit you have, but if the roofers put a B-Vent cap on a Direct Vent unit, it would definitely cause issues.
It would allow the burnt combustion air to intermix with the incoming fresh air & the burner would shut itself down
because it wouldn't get enough oxygen.

 

[gjacquin]

Thanks for the reply Daksy. I have a Travis Industries 864 TRV, manual calls for DuraVent 46DVA-VCH but the cap they put on looks just like the one in the picture I attached. I see now it's a B-type, whatever that means. Too bad roofers don't know better. Caused me a lot of time, frustration, and cost.

 

[DAKSY]

B-Vent uses combustion air from inside the building the unit is installed in.
Direct vent has a coaxial pipe. The outer ones draws air in thru the cap &
the inner one exhausts the spent gases thru the cap ABOVE the intake.
Your B-Vent cap was mixing the incoming & exhaust gases & the burner was
starved for oxygen.

 

[gjacquin]

Makes total sense. Hence it would fire right up no problem, then shut itself down. I wonder how many people have non-working fireplaces due to roofers' ignorance of vent caps.