Pellet Hopper Fire

[VTrider]

Okay, these are the types of threads that 'spark' my interest - no pun intended. Seriously though, a hopper fire is such a rare and serious incident that should be one of the main concerns for every member here. I think the focus of this thread is to understand first, why this has happened and what to do to prevent this in the future?

Smokey, you mentioned that all pellet stoves can have hopper fires. I understand that this is a possibility of course, considering we are all dealing with a combustion machine - but let's face it, with a properly installed stove under the correct circumstances these things just don't 'usually' happen without some sort of key variable like an unmaintained stove, improper venting, etc.?

I find it hard to believe that a company would design a stove that could kill you and your family and burn down your house if it looses power during operation - then again..I just don't know? So, was it inadequate vertical exhaust rise / draft?, something inherent about bottom-feeder pellet design, or what? I too heat from the basement with a similar stove which runs 24/7 and this scenario scares the hell outta me!

 

[SmokeyTheBear]

Yes VTrider there are things that usually have to be in place for there to be a hopper fire, however if you go through all of the non hopper fire threads on here you soon discover there is more than ample conditions extent in the installed stove base that could end in that manner.

Topping the list are the self installs that do not follow the instructions in the fine manual.

Then we have more than just one or two "professional" installs that also fall in that category.

However even if the install is by the book, what transpires next frequently isn't.

I and others keep harping on some of the more egregious installation and operational ones, but over and over and over the same ones keep showing up.

If I tell someone not to fire their stove up until they have the cause for the creosote they are indicating is appearing where it shouldn't be fixed and the system cleaned and the "repairman" says it is just sweating in the chimney I want to reach out and apply some physical reinforcement.

As I've said these stoves are generally pretty good at containing a hopper fire provided .... but smoke they will.

You have electrical safeties that are fine until you lose the juice to run them, then there are are gaskets that contain even smoke, there is venting that allows the smoke to exit the stove, and so on goes the list, however these things need periodic cleaning, checking, and maintenance (deferment isn't really an option).

 

[Bioburner]

Something we all need to also look at is the care to which a product is manufactured. Manufacturing standards not being adhered to in China leads to many problems. USSC letting the Chinese make the window stove and now it had problems with poor metal in the burn pot. A good design can be poorly made and leads to the problems.

 

[SidecarFlip]

Something we all need to also look at is the care to which a product is manufactured. Manufacturing standards not being adhered to in China leads to many problems. USSC letting the Chinese make the window stove and now it had problems with poor metal in the burn pot. A good design can be poorly made and leads to the problems.

Absolutely. However, not all Chinese stuff is substandard. It depends entirely on oversight by the OEM and what they require as to quality. Let a Chinese manufacturer (of anything) have an unfettered control and things go downhill fast....

Case in point (for reference) for me is the Arborists saw I purchased this fall. It's a Tanaka which is actually a Hitachi brand (Japanese) made in China and it's a well put together, very reliable chainsaw but (and this is a biggie)..... I suspect that there is strict oversight and quality standards involved on the part of Hitachi.

Some items, like grey iron castings, are almost unobtainable domestically at a reasonable and competitive price. The castings on most stoves will be offshore, maybe not china but most likely, but again, oversight is paramount and profit versus quality needs to be addressed. That applies to everything, not just stoves btw.

 

[hyfire]

FYI this is not a Chinese stove, its Canadian made and CSA approved.

 

[sass_eco65]

Here is the stove setup from inside. I will post a pic from outside in a few. Also, the stove we have is the 2010 model, not the 2012 so the manuals are slightly different. Not sure if that makes a difference for the backdraft shutter.

The hopper lid does not seal like other units would... I dont know why. If you look at pictures of the stove, you can actually see that the hopper lid sits up a bit. We had about 2 bags in the hopper when it happened.

So how exactly do I prevent this from happening with my new setup? I would like a top fed unit for piece of mind.

I could go to small claims, but the owners manual states that they do not cover power failures. Im sure that does not go to the extent of them being able to burn the house down.. I just dont think it would settle as fast as some might think. Also, we have not notified our insurance as the fire department said we only need to if we want to make a claim. Trying to weigh variables. Besides the slight hint of smoke left in the house, the only damage was done to the stove.

 

[sass_eco65]

Here is outside. The OAK is at the same level as where the pipe comes out the wall, and is just to the left. Don't have a pic of it.

 

[sass_eco65]

I have a eco-65 and had a power outage, I had no visible smoke in the room, but did have some smoke smell and still maintained a negative draft of .05" w.c. However I do have a natural draft since I have 10 of vertical rise( 4 inside and 6 outside). and my OAK is 18" from the ground. I do regret to hear about the hopper fire and it sounds very scary, but having the room fill with smoke sounds like a draft problem that led to your loss of neg pressure at the auger chute at the power outage. The manual states you need a min of 3' vertical rise after a horizontal termination. You said you cleaned the stove but did you clean the horizontal flue section of your venting? This is where its critical as the ash builds up very quickly.

The manual states that you need a minimum total vertical rise of 3'? Pretty sure it doesn't state it has to be that after a horizontal run. Would a single foot extra outside really have made the difference between a fire or not a fire? I can understand maybe 4+ feet. Either way, the installer followed what the manual said and I had 2 inspections. We have not cleaned the horizontal section of venting yet as the stove had only been installed for a month.

 

[hyfire]

The manual does state that yes, but like you said would 1 foot really have made a difference? I don;t know, but without putting a pressure gauge on it, you won;t know how well its going to work. Is the house tightly sealed? If you burned 1 bag a day for a month the flue would be clogged more than 50 % based on from what I have seen with mine, and I clean it every 30 bags. If it were my setup I would change the outside T fitting to a 2 way tee fitting and add at least 6 feet to it in vertical height, this way you can actually clean the horizontal flue.

 

[sass_eco65]

The manual does state that yes, but like you said would 1 foot really have made a difference? I don;t know, but without putting a pressure gauge on it, you won;t know how well its going to work. Is the house tightly sealed? If you burned 1 bag a day for a month the flue would be clogged more than 50 % based on from what I have seen with mine, and I clean it every 30 bags. If it were my setup I would change the outside T fitting to a 2 way tee fitting and add at least 6 feet to it in vertical height, this way you can actually clean the horizontal flue.

Yes, with the new setup we will be putting the 2 way tee on it. I will however be buying a different stove. The guys at the fireplace store I spoke to keep saying all you need is a foot or two of vertical rise outside for their stoves. I am wondering if I should tell them I want an additional 6'. Although there may be an air issue with the setup we have now, there are no safety features in place on the eco65 to prevent the hopper from catching fire. Smoke is one thing... fire is another. The fact that air can get under the hopper lid on the old ones is scary enough on its own, let alone the stove design.

 

[hyfire]

Just get a draft gauge and test it 1st before you remove the stove, id be interested to see the results, you can get one 30-50 on ebay, and you should keep it also on the next stove you get.

 

[CaptSpiff]

sass_eco65,
The first question you need to answer is: will you ever trust this stove design again, and will your wife trust it?

If yes, then you must really think about a ups (like for your computer) to continue the electrical supply at least long enough for the shutdown cycle. I think this is even more important on the horizontal auger design such as the "65". If I recall correctly the shutdown cycle stops the upper auger (hopper auger) and allows the lower auger (burn pot auger) to continue feeding. This breaks the "fuel bridge" and prevents any burning to migrate into the hopper.

During the power failure both augers stop and a burn path exists to the hopper. Normally the "65" is very air hungry, and I was told the fire will "snuff out" if both the input combustion fan and the output combustion fan stop together. But maybe your venting draft is strong and the fire continued with enough fresh air to get to the hopper. I've never seen that, but there's always a first.

There are several threads on UPS applications here. Concentrate on the ones that talk about a 1 hour run time, ignore the ones suggesting 8-10 hour runs because you'll need several deep-cycle batteries to support that.

Good luck. Looking at your install, both inside and out, it looked pretty good to me. Raising your outside exhaust vent another 2 to 4 feet would be OK, but that present setup should work fine. My only worry is how did you clean the horizontal back down to your stove Tee?

 

[CaptSpiff]

Need to follow up my own post cause I have a couple of questions:

Are those before fire or after fire pictures? I ask cause everything looks so clean.

You said the smoke was so thick it was hard to see. Did you actually see flames in the hopper, or only smoke?

Does the "65" have an "air wash" system on the glass in the door? This is typically a place where smoke will exit during power loss on other stoves.

The "65" has a back draft flapper in the OAK connector. Would that close and inhibit the natural draft during power loss?

This one may be embarrassing but, do you have interconnected (battery backup) smoke detectors in the basement & upstairs?

 

[hyfire]

The 65 does have an air wash around the lower horizontal section of the glass, and it has no back draft flapper that I know of, at least on my model, which is a 2012.

 

[SmokeyTheBear]

The manual states that you need a minimum total vertical rise of 3'? Pretty sure it doesn't state it has to be that after a horizontal run. Would a single foot extra outside really have made the difference between a fire or not a fire? I can understand maybe 4+ feet. Either way, the installer followed what the manual said and I had 2 inspections. We have not cleaned the horizontal section of venting yet as the stove had only been installed for a month.

Actually IIRC from when I read your manual I would read the termination requirements to be in excess of 3' above the OAK depending on what your code defines certain terms to mean. The US clearances are a bit clearer in certain cases. I'd grill that inspector.

I don't have actual measurements on how much horizontal is in the vent run or if there is any of the venting going downward You have an EVL of at least 28 which is going to cause a lot of ash to be deposited in the vent run especially with the vent termination so close to the OAK which would likely cause a poor burn as evidenced by the soot stain on the termination.

Between the ash and normal vent restriction it would likely be very difficult to sustain a natural draft during a power outage.

 

[lagger]

My Lopi AGP has a disk system (bottom feed) that effectively isolates the auger from the hopper, that is there is no direct link to the hopper and a bridge of pellets is not possible (or so they say) The disk turns horizontally to bring pellets on one side to the auger before being fed to the burn platform, the AGP has more of a platform than a pot, it is angled at 14 deg toward the ash pan to facilitate dropping the ashes as new pellets are fed from the rear

 

[Pellet-King]

You need a good battery backup, would of prevented this in the first place, Horizontal "pusher" style stoves always Irked me, Harmon uses it, drop chute I really cnt see how it could cause a hopper fire

 

[hyfire]

By looking at the pics, looks like he has about 1 foot horizontal plus the fitting distance, but I;m just guessing.. the OP would know.

 

[SmokeyTheBear]

You need a good battery backup, would of prevented this in the first place, Horizontal "pusher" style stoves always Irked me, Harmon uses it, drop chute I really cnt see how it could cause a hopper fire

Don't let me burst your bubble then, you keep right on believing that.

Or follow the consequences of a poorly adjusted damper, plenty of ash in the stove's exhaust channels.

I believe Rod posted a few pictures in his stuff, links to which are some of stickies at the top of this forum room.

As a further example I present https://www.hearth.com/talk/threads/englander-25-pah-issues.137024/page-3#post-1842161

 

[F4jock]

sass_eco65,
The first question you need to answer is: will you ever trust this stove design again, and will your wife trust it?

If yes, then you must really think about a ups (like for your computer) to continue the electrical supply at least long enough for the shutdown cycle. I think this is even more important on the horizontal auger design such as the "65". If I recall correctly the shutdown cycle stops the upper auger (hopper auger) and allows the lower auger (burn pot auger) to continue feeding. This breaks the "fuel bridge" and prevents any burning to migrate into the hopper.

During the power failure both augers stop and a burn path exists to the hopper. Normally the "65" is very air hungry, and I was told the fire will "snuff out" if both the input combustion fan and the output combustion fan stop together. But maybe your venting draft is strong and the fire continued with enough fresh air to get to the hopper. I've never seen that, but there's always a first.

There are several threads on UPS applications here. Concentrate on the ones that talk about a 1 hour run time, ignore the ones suggesting 8-10 hour runs because you'll need several deep-cycle batteries to support that.

Good luck. Looking at your install, both inside and out, it looked pretty good to me. Raising your outside exhaust vent another 2 to 4 feet would be OK, but that present setup should work fine. My only worry is how did you clean the horizontal back down to your stove Tee?

Ignore longer UPS run times? So. . . . what if I'm away or asleep and the power fails? If the stove doesn't go into a hard and permanent shutdown on power fail an hour ain't gonna cut it. I want as much leeway as I can get to be sure I can take corrective measures. A couple of deep cycle batteries and a charging system / inverter is a small price to pay for safety. And, for me anyway, one hopper fire caused by poor stove design and not a correctable error on my part would be one too many. Stove would be scrapped.

 

[chken]

Okay, just skimmed the thread, so I may have missed it, but what can the OP do now to prevent future fires?

Does the stove have an auto shutdown when it senses a modified sine wave like Harmans do? If it does, then a UPS with a modified sine wave would work, wouldn't it?

As for small claims court, and the disclaimer in the manual. I'm not a lawyer, but my understanding is that disclaimers are not worth the paper they are written on, unless the owner explicitly agrees to them.

 

[F4jock]

Okay, just skimmed the thread, so I may have missed it, but what can the OP do now to prevent future fires?

Does the stove have an auto shutdown when it senses a modified sine wave like Harmans do? If it does, then a UPS with a modified sine wave would work, wouldn't it?

As for small claims court, and the disclaimer in the manual. I'm not a lawyer, but my understanding is that disclaimers are not worth the paper they are written on, unless the owner explicitly agrees to them.

And it doesn't excuse poor design or design negligence. (Daughter is corporate council for a product liability firm.) Manufacturer is responsible for insuring safety under all operating conditions that can be reasonably anticipated and or for which there is a reasonable precedent. I'd say power failure meets that criteria. As well, it can be shown that other manufacturers have taken successful steps to provide for that eventuality so the maker of this stove should have known it was necessary.

 

[BrotherBart]

Gotta ask. What position was the fresh air intake damper in.

 

[hyfire]

Gotta ask. What position was the fresh air intake damper in.

And it doesn't excuse poor design or design negligence. (Daughter is corporate council for a product liability firm.) Manufacturer is responsible for insuring safety under all operating conditions that can be reasonably anticipated and or for which there is a reasonable precedent. I'd say power failure meets that criteria. As well, it can be shown that other manufacturers have taken successful steps to provide for that eventuality so the maker of this stove should have known it was necessary.

According to the manual the installation may not meet the requirements outlined. The OAk being at least 3 feet lower than the exhaust discharge, a 3 foot vertical rise after a horizontal run. This would be a hard battle..but I do agree it should be a safer design.

 

[F4jock]

According to the manual the installation may not meet the requirements outlined. The OAk being at least 3 feet lower than the exhaust discharge, a 3 foot vertical rise after a horizontal run. This would be a hard battle..but I do agree it should be a safer design.

Defense would have to show that the "improper installation" affected operation in such a way as to cause or contribute to the fire moreso than faulty design.