Puffback Blew Pipe Off of Chimney and Stove

Fields Controls does not recommend having barometric dampers in what is known as a bullhead configuration as pictured by CoalHeat.

I tried that once - it was a bitch to get the baro tuned properly. I assume that is why Field Controls recommends against it...the baro is not calibrated for that configuration.

I don't have any adjustable elbows in the stove pipe in shop. I have Tee's. Wouldn't be afraid of using an adjustable elbow. I've used them before.

2001Sierra wrote:Fields Controls does not recommend having barometric dampers in what is known as a bullhead configuration as pictured by CoalHeat.

It was shown as an acceptable mounting position in the instructions when I installed it. Since that time it was removed from the install diagram. It is considered neither vertical or horizontal, therefore calibration with a manometer is required. Been running it that way for 10 years now.

This morning, the installer cemented the chimney connector pipe in the wall (per para 9.7.1 of NFPA 211), and said he'd order a fixed 90 and install at no charge. Didn't seem too experienced with hand fired stoves, was not aware that puffbacks happen.

In fact, installation failed para 9.7.1 (2) for years (bought home from grandmother) as the pipe to the chimney has always been loose. Combined with the fixed 90, it'll be safer than it's been in a long time.

Of course, wife is all bent out of shape over it. Doesn't trust his work, doesn't trust my recommendations even after showing her the applicable code (because I'm not a professional or something). I said if I can't handle screwing some pipe together with sheet metal screws we have no business being homeonwers, and that the only other option is to get rid of it since 2 professionals have contributed to this in some way so far (both missed the loose pipe) -- but she loves saving money on heating costs and the heat it adds to the house, so we'll see how that turns out

Some coals have more volatile matter than others. I had some nut size that made some pretty spectacular flashes when it ignited

https://youtu.be/4UE3Zi1Jjbk

If you load a lot at once just keep the load door cracked a hair till it's really ripping good.

I have looked at the elbow that failed and I would still consider them if the pipe is properly

supported thereby eliminating the strain on the ell.

It looks to me that the upper fitting was blown out of the wall thimble by the backfire.

The upper ell needs to be restrained to prevent it from pulling out of the thimble.

The lower ell is not required to support the weight of the pipe and much less being able

to flex away from the chimney.

Years ago I remember a piece of steel that extended into the thimble along the bottom of the

pipe and was bent downward into the chimney to keep the fitting from pulling out . It may have

been part of the decorative trim collar.

BigBarney

I have experienced a puffback or two but never one powerful enough to blow pipes apart thank goodness.

My guess is that no matter how well built, a strong enough puffback is coming out somewhere. Probably better out the pipes than a fastened door or door glass. With that being said I just don't think there's blame to be placed here. Its unfortunate for sure but these sort of things happen.

In a former life I use to build racecar chassis. Would never fail that some guy would wad one up then come asking what we could do to minimize damage. Our response was that you can't fly a plane into the side of a mountain and not expect some thing to break. Not the same thing I know but there is a reason why you don't see many newly built houses with chimneys.

gbru316 wrote:This morning, the installer cemented the chimney connector pipe in the wall (per para 9.7.1 of NFPA 211), and said he'd order a fixed 90 and install at no charge. Didn't seem too experienced with hand fired stoves, was not aware that puffbacks happen.

In fact, installation failed para 9.7.1 (2) for years (bought home from grandmother) as the pipe to the chimney has always been loose. Combined with the fixed 90, it'll be safer than it's been in a long time.

Of course, wife is all bent out of shape over it. Doesn't trust his work, doesn't trust my recommendations even after showing her the applicable code (because I'm not a professional or something). I said if I can't handle screwing some pipe together with sheet metal screws we have no business being homeonwers, and that the only other option is to get rid of it since 2 professionals have contributed to this in some way so far (both missed the loose pipe) -- but she loves saving money on heating costs and the heat it adds to the house, so we'll see how that turns out

That's why I always blame the wifey first. LOL

"Do you know what you're doing?" says the wifey.

"I watched 3 youtube vids ... I'm an expert!" says the guy who just shocked himself ....

gbru316 wrote:This morning, the installer cemented the chimney connector pipe in the wall (per para 9.7.1 of NFPA 211), and said he'd order a fixed 90 and install at no charge. Didn't seem too experienced with hand fired stoves, was not aware that puffbacks happen.

In fact, installation failed para 9.7.1 (2) for years (bought home from grandmother) as the pipe to the chimney has always been loose. Combined with the fixed 90, it'll be safer than it's been in a long time.

Of course, wife is all bent out of shape over it. Doesn't trust his work, doesn't trust my recommendations even after showing her the applicable code (because I'm not a professional or something). I said if I can't handle screwing some pipe together with sheet metal screws we have no business being homeonwers, and that the only other option is to get rid of it since 2 professionals have contributed to this in some way so far (both missed the loose pipe) -- but she loves saving money on heating costs and the heat it adds to the house, so we'll see how that turns out

Sounds like a good fix to me, and your installer is doing right by you.

Modify your tending routine a little (never add more coal than what is already burning brightly in the stove, leave some burning coal exposed to act like a "pilot light", and use some over-fire air after tending), and it should be smooth sailing from here.

davidmcbeth3 wrote: That's why I always blame the wifey first. LOL

"Do you know what you're doing?" says the wifey.

"I watched 3 youtube vids ... I'm an expert!" says the guy who just shocked himself ....

I'm an electrical engineer, I still shock myself sometimes

Rob R. wrote: Sounds like a good fix to me, and your installer is doing right by you.

Modify your tending routine a little (never add more coal than what is already burning brightly in the stove, leave some burning coal exposed to act like a "pilot light", and use some over-fire air after tending), and it should be smooth sailing from here.

Agreed, no complaints with how installer is handling this. And will definitely leave loading door cracked until flames appear next time I run into this situation, since there are no adjustable over-fire intakes in the mark iii.

philthy wrote:Not the same thing I know but there is a reason why you don't see many newly built houses with chimneys.

It's called cheap construction.

Read in prior message an intent to go to your insurance company to fix the carpet.

Think several times about this, they will interpret that 50 #s of burning coal is forever not safe with rates likely jacked up not to consider cancellation by current or future companies (they share claim info with lookback period ~4-5 years ).

That must of been a real gollywhomper of a blow. A good lesson for all of us. Its one reason why a stoker replaced my Mark II after some years. Though I miss the dancing blue ladies.

Ug

Uglysquirrel wrote:Read in prior message an intent to go to your insurance company to fix the carpet.

Think several times about this, they will interpret that 50 #s of burning coal is forever not safe with rates likely jacked up not to consider cancellation by current or future companies (they share claim info with lookback period ~4-5 years ).

That must of been a real gollywhomper of a blow. A good lesson for all of us. Its one reason why a stoker replaced my Mark II after some years. Though I miss the dancing blue ladies.

Ug

No, installer said he was going to go through his insurance company for the carpet.

One thing I will be doing before I fire it back up next year is filling a bucket or two with sand, just in case I ever need to shut it down quickly.