What causes the "pop"?

[RedRanger]

Our Napoleon propane insert sometimes pops when turned on. But only intermittenly,sometimes it pops and sometimes it doesn`t. Does this have something to do with atmospheric pressure or other weather related effects?

It has been a great little insert since we bought it int he fall of 03 no problems with it at all. Passed inspection even when it popped while the inspector was fiddling with it. I still would like to know what causes this however. Do the experts have an opinion?

 

[ControlFreak]

I have a Napoleon 1401 wood insert. Sometimes when it's heating up from a cold start it will make a "bong" sound. Sounds like a steel panel somewhere in back is flexing in the middle. Maybe when it's cold it flexes in, but when hot it flexes out. It also has a the thermo-disk switch that was used to turn on the fans. (I don't use that any more). That makes a click, or pop, when it switches. Then when it first heats up, it makes a lot of ticking sounds as things expand. Then there's the "new fire" smell that it makes after it has been cool for the whole summer. Then there's the snap crackle pop when using pine kindling. Don't you just love these things?

Now, if it ever starts talking to you, it's time to get a checkup.

 

[jtp10181]

I think sonny is talking about a slight delayed ignition causing a small "boom" in the firebox. This is pretty normal for LP gas because it is heavier than air. If you ever hear a different burning sound after it does that, like a afterburner on a jet engine, turn it off right away. Sometimes the delayed ignition cause cause the gas to start burning in the tube below the burner pan. If it never does that and its just a small boom I would not worry about it.

 

[RedRanger]

Thanks JTP:

you described it better than I did in my post. exactly a small boom, then everything is fine. was just curious why it doesn`t always happen? seems quite random. no concerns here, just curious about the way it only does it randomly?

 

[jtp10181]

Could be a lot of factors, probably environmental.