Loud Bang from Progress Hybrid

[progress_stover]

Hi All,

I bought a Progress Hybrid and had it installed March 2022. It is my second year with it and I'm generally pleased with the performance. This season, I started to hear a loud "BANG" from inside the firebox or under the cooktop as it's heating up. It happens every time the stove is heating up and seems to be getting worse. I reached out to Woodstock all last week but they've been hard to get a hold of. The stove has never been over-fired and is usually run in the 350-450 range (stove top temps).

Any experience with this loud noise and what it could mean? Do you think the stove is unsafe to operate?

 

[mellow]

Sounds like it is back puffing, ie.. igniting unburnt gases in the firebox. Usually a draft issue. Sometimes doing a top down style fire helps warm up the pipes increasing your draft before you close the bypass.

 

[progress_stover]

Sounds like it is back puffing, ie.. igniting unburnt gases in the firebox. Usually a draft issue. Sometimes doing a top down style fire helps warm up the pipes increasing your draft before you close the bypass.

I've experienced backpuffing and don't think this is what it is. It sounds more like the steel is flexing during the temperature change from cold to hot.

I always light top-down style and have excellent draft. 25 ft. pipe internal chim

 

[begreen]

Is this with the bypass open or closed?
If not backpuffing, then something is stressing out metal as the stove heats up. Today is a holiday, but keep trying to get Woodstock support tomorrow. It's the start of the heating season so they are busy so be patient.

 

[progress_stover]

Is this with the bypass open or closed?
If not backpuffing, then something is stressing out metal as the stove heats up. Today is a holiday, but keep trying to get Woodstock support tomorrow. It's the start of the heating season so they are busy so be patient.

It happens usually after I close the bypass, but last night I heard it when the bypass was open (also during the warm-up phase).

I've read some other posts on here with similar issues and some of them say that it could be due to an 'unlevel' stove. My hearth (and therefore my stove) is 'tilted' forward slightly, but not sure if that could be the issue? Can't see how that could be causing the problem.

I took a look under the hood this morning and noticed that some joints were 'loose/crusty' (see pictures).

 

[begreen]

It wouldn't hurt to shim up the front feet temporarily to see if that helps. The heat exchanger warming up might be causing some movement? Just spitballing here, I have not used this stove. IIRC, the PH is a steel stove wrapped inside and out with soapstone. If so, there are several places where expansion is happening as the stove heats up but I would think that the heat exchanger is where this would occur first.

 

[Highbeam]

Definitely one of their better looking stoves.

 

[progress_stover]

Update: Heard back from Woodstock. They seem to think that it has to do with one of the heat shields flexing during warm-up. No real solution was provided, but they seemed to not be very concerned and that the stove should be safe to run. I mentioned the possibility of a weld cracking and they said that that was very unlikely to be the case, given the way the stove is constructed. She said most likely it's just because there are so many different metals with the steel and cast iron interfacing one another that their expansion/contraction at different rates can explain these loud bangs.

 

[begreen]

Temporarily loosen up the bolts holding on the rear shielding to help isolate the issue.

 

[mellow]

Not sure how involved you want to get into this but a heatgun aimed at the possible areas from the inside while the stove is cold might help you track down the issue.

1700 Watt 14 Amp 108 Temperature High Output Heat Gun

Amazing deals on this 1700 Watt 108 Temp Dual Fan Heat Gun at Harbor Freight. Quality tools & low prices.

www.harborfreight.com

 

[progress_stover]

Hi All, The issue is still ongoing. I was able to get a recording of the sound to send to Woodstock. Waiting to hear back from them.

 

[moresnow]

As mentioned it sounds like heat shielding expanding. As advised above By BG can/have you loosened the shielding for a load?
Let us know what you figure out.

 

[progress_stover]

Hey all, turns out it wasn't a heat shield flexing as originally thought. It is a combustion noise. Apparently there are gasses building up in pockets under the cooktop and that the loud bang is combustion of these gasses once the stove reaches a high enough temp. After sharing the recording with Woodstock, they were adamant that this was occurring due to me burning super dry wood and very small splits. They suggested burning larger splits that had a bit higher moisture content. After doing this, the problem seems to have resolved. Thanks for all your input and help along the way!

 

[begreen]

Thanks for the update. That's interesting information I have heard of and experienced this with poorly seasoned wood, but not with super dry wood and small splits.