Eagle Fifth Wheel popping vent sound w/heat

[TxLoser]

I noticed on my trip to NM where I had to use the furnace that I kept hearing a sounds like metal expanding/popping. Never noticed this prior years. Is there a potential issue with my duct work or just something I never noticed. Seemed to operate correctly. Best I could tell it must have come the rectangular duct that runs under the floor above the basement.

[RedHorse1]

Could it be an issue with the burner? I’ve seen WHs with a partially blocked burner tube. It’ll ignite but poor burning causes unburnt gas to accumulate and it will “pop” when it ignites. Look around the exhaust and see if the noise is coming from the furnace and/or soot deposits around the exhaust vent.

[TxLoser]

I’ll have a look. Have to restring a blind this week, so while I’m at it, I may pull both basement walls so I can get in there and have a look. Don’t much like the unburned gas igniting idea. Seems like a bomb in the making.

[TxLoser]

So, I just fired up the gas log fireplace in my stick and bricks and the vent/flu made the exact same sound. The metal suddenly expanded, making a pop. Wonder why my trailer never did that past years

[TxLoser]

Officially solved my banging noise issue with the heater running. As expected, the sheet metal duct under the bedroom floor pops when it get warm. Must’ve gotten deformed at some point. Don’t see anything visible, but I can see it jump a little when under there after it gets some heat on it. Case closed.

[RedHorse1]

Originally Posted by TxLoser

Officially solved my banging noise issue with the heater running. As expected, the sheet metal duct under the bedroom floor pops when it get warm. Must’ve gotten deformed at some point. Don’t see anything visible, but I can see it jump a little when under there after it gets some heat on it. Case closed.

That’s very interesting, thx for the update!
Just when I thought I knew everything something like this pops up.