Had a hopper fire last night, need advice

[goathead]

Thankfully my dog woke us up as the house was getting smokey since my smoke detector (which had a new battery as of the time change) failed as well. What a night.

So I went downstairs and found smoke coming out of the hopper. When I opened up, I could see the orange glow of the pellets down near the feed. I immediately started scooping out the unburnt pellets into my ash bucket and as I kept scooping, the pellets were getting more air and flaring up. Not a fun situation. So, I wound up putting a little bit of water on it to knock it down so I could keep getting the pellets out. Finally got it all settled after about an hour and took the stove apart to make sure I didn't miss anything.

Now I'm trying to figure out what went wrong and if the stove is still functional.

Stove - Quadra-fire Castile insert

When I went through the stove and checked the safety devices to see what tripped.

Snap disk 2 - overfire did not trip

Snap disk 3 - burnback into hopper DID trip

So, I'm confused as to why I had the problem unless my snap disk 2 is bad. It looks like inside the fire box got VERY hot. Everything is black and orange with pellets burnt outside the fire pot, almost like it kept feeding. Glass is totally black. Overfeed and overfire?

My exhaust motor also seems to have issues now as well as it seems tougher than normal to turn. Could the heat have cooked the bearings? Or maybe the motor failed and caused the chain of events?

The auger is cooked black and shiny. Not sure if the motor is still good or not. I'll have to check this later today.

As far as maintenance goes on the stove. I had done my weekly cleaning about 3 days earlier. This is the tear down cleaning the heat exchangers and behind the fire brick. I clean the firepot daily so that should have been fine.

Pellets - I only use New England Wood Pellets which seem to be the best as far as quality goes from the other brands I bought.

I'm at a loss. I think it had to be a multiple failure of items to cause it. I've always felt safe running the stove overnight or while I'm gone, but this has me second guessing. Also, I've got to see if I can clean the stove since the hopper and and the feed tube are all burned black. I'm hoping that I can. I plugged the stove in and it didn't even turn on so I'm assuming that the fact that the safety switches were tripped caused it.

Any help or advice is appreciated. Thanks.

 

[stoveguy2esw]

looking at the second picture (assuming nothing was touched prior to the shot) i'd say the exhaust blower failed and the stove fed for a time before it stopped feeding, thats likley where the ash around the chute came from ,the pot would have piled up and fuel would have nowhere to go, combine that with possible negative pressure (does the instert have an oak?) or an at least partially stopped up flue. smoke is pulled or forced up the chute from the lack of exhaust allowing positive pressure to build in the front of the stove, heat and all, cooks the pellets all the way back , usually a sealed feed system and hopper will help to keep this from happening, also the stove should have had a trip switch of some sort that would have killed the auger as soon as the exhaust blower stopped. if this stove is so equipped i'd take a look at that particular sensor as well assuming it didnt trip and stop the auger from continuing to feed.

burnbacks arent common , usually it takes more than one component failing to cause this usually exhaust blower being one ,and its monitoring sensor being the other. pellet stoves are rigorously tested to assure that the design can withstand and contain a hopper fire, usually the only thing getting out of the stove is smoke.

i do not really know how the quads are set up to avoid this so i cant point you to a direct part or sensor, but usually the setup is laid out in their tech manual.

hope this helps ya.

 

[richg]

How old is the stove? Any chance of it still being under warranty?

 

[goathead]

looking at the second picture (assuming nothing was touched prior to the shot) i'd say the exhaust blower failed and the stove fed for a time before it stopped feeding, thats likley where the ash around the chute came from ,the pot would have piled up and fuel would have nowhere to go, combine that with possible negative pressure (does the instert have an oak?) or an at least partially stopped up flue. smoke is pulled or forced up the chute from the lack of exhaust allowing positive pressure to build in the front of the stove, heat and all, cooks the pellets all the way back , usually a sealed feed system and hopper will help to keep this from happening, also the stove should have had a trip switch of some sort that would have killed the auger as soon as the exhaust blower stopped. if this stove is so equipped i'd take a look at that particular sensor as well assuming it didnt trip and stop the auger from continuing to feed.

burnbacks arent common , usually it takes more than one component failing to cause this usually exhaust blower being one ,and its monitoring sensor being the other. pellet stoves are rigorously tested to assure that the design can withstand and contain a hopper fire, usually the only thing getting out of the stove is smoke.

i do not really know how the quads are set up to avoid this so i cant point you to a direct part or sensor, but usually the setup is laid out in their tech manual.

hope this helps ya.

The only thing I touched in that picture is the white mark on the fire brick. I gave it a quick scrape to see how thick the soot was. The quads have a vacuum switch as well which should trip if the exhaust stops so I'm wondering if the vacuum switch failed also? I might bring it up to the place I bought it and have them take a look at it. I have to totally disassemble it to clean it thoroughly anyhow.

For the other poster, The stove is either 4 or 5 years old so unfortunately it's out of warranty.

 

[Czech]

My mom has had two now, same stove make and model. What is your vent config? The first one she had, the dealer took the stove back and replaced with new. She maintains it very well, but had another fire a few months ago. I tore the stove apart, removed the auger, cleaned everything. Even though I had cleaned her vent in the fall, it was packed with ash (good quality fuel, I burn the same). Other than the tripped snap disk 3 and a very dirty auger that needed to be buffed clean, the stove was fine. So here's my theory in her case. I think he vent config (flex 20' up) prevents the fly ash from leaving the stack, and then occludes the vent causing an inefficient burn and air back pressure that flows up the drop tube. Because the stove is neg pressure, the only way you can get combustion up the drop tube and into the hopper is with some sort of air flow. Like I said, her vent was almost totally occluded and nothing tripped, all the safe guards checked out electronically. There is an upgrade for this stove from Quad, it is suppose to improve airflow, in fact my dealer just called to say it is in. Part number is UK-30KPEL, demand that it be no charge because of your problems! I would also have your dealer or you contact Quad about this, they should take it VERY seriously. Search the site for hopper fire or quad upgrade for previous threads. I have a free standing Castile and cannot make my stove do this, I've tried by cheating it even. Won't happen without back pressure to combust the fuel up the drop tube. All this said, I think Quad has an issue with the inserts.

 

[SmokeyTheBear]

By any chance is the hopper area open to the chimney or firebox area of the fireplace?

Just wondering a chimney draft effect working on an insert could perhaps lead to an air path that would setup in the chute.

I've had a few pileups and the pellets never get any air through the chute the fire slowly dies. Then I also don't have that particular stove.

 

[webbie]

Is the chimney lined to the top?

I guess it goes without saying that a backup battery operated smoke detector AND a CO or combo one is a cheap investment. Personally, I am VERY frightened of fire and try to be extra safe when anything burning is concerned. Heck, my son yesterday pulled a smoldering bagel out of the toaster and tried to throw it into the kitchen trash..I would not let him! I made him stick it into a bowl full of water in the kitchen sink for a few minutes. No use taking chances......

 

[Czech]

Was that your bagel or his Craig? My kids did the hard roll in the microwave deal, looked like a piece of charcoal and tinked like a cooling engine for an hour. Good point about CO's and smoke, an extinguisher mounted at the room entry point (not right by the stove!) is also a must have. Just came home with the upgrade kit, let me see if I can do some scans of the instructions.....

 

[Czech]

Scans, not the best quality, let me know if anyone wants them email or pm'd.

 

[Czech]

Ok Craig, you have mail! I'll having mime errors, I'll send the rest to you in the hope you can post. Thanks!

 

[Czech]

Third time a charm?

 

[Czech]

One last one, cross your fingers....

 

[Czech]

Work?

 

[Czech]

OK, there you have it. The dealers I talked to had no idea this existed, you may need to educate them fyi.

 

[goathead]

Wow, Thanks for the info GotzTheHotz. I'll print that out when I go to the dealer. I think I'm going to throw the stove in my truck and bring it up there to see what their opinion is. Haven't had a ton of time to go through it today but the auger is covered in what looks and feels like black tar and the cork gasket is fully roasted.

As far as the vent set up. I have my stove on a lower level and ran a 4" flex pipe all the way up so figure 8' plus another 12-15' for the upstairs and the peak? That's what the inspector was looking for when I had it installed. I've always had a good draft. Even when cleaning the stove and having the fire brink out there was always a natural venting up the exhaust.

I'm just so disgusted and really bummed out. I've had my stove for 5 years and touted the safety features and love being able to heat my house with a renewable resource...ok, and save money from using my electric heat. Then on top of it, my smoke detector failed. Needless to say I picked up all new ones today and my friend who's a firefighter in town brought over CO detectors for me for the upstairs and downstairs. I just keep thinking how lucky we are that my dog woke us up otherwise who knows what could have happened with a 1/2 full hopper full of pellets.

Thanks everyone for the help and input. Definitely have given me a lot to check out and some interesting history on the stove. I'll be checking this out online see if I can find anything else.

 

[Czech]

Dogs are good! Glad you and yours are ok, hopefully the info here will help.

 

[Nicholas440]

Is that upgrade kit for the older Castile inserts, or is it also for the newest models? I have a new Castile insert, and mine looks like those photos, I only have rope around the center brick, and none on the outer two bricks, however my bricks are straight across they are not angled inwards.

After reading about that hopper fire I dont feel as confident in my Quadrafires safety features. I had an incident a few weeks ago where I looked over at my insert and I immediately saw the fire in the box getting very wild and out of control, it was always active and bright yellowish white almost, only this time it was going crazy, and the Quad insert was making some awful sounding noises, not mechanical sounds it was from the fire trying to get out up the top baffle. The entire firebox was engulfed in flame and black smoke, the fire was a very dull orange and lazy but it seemed like it just could not exhaust fast enough, luckily I was right there and saw it happening, this fire was not just high flame it was totally out of control, so I immediately shut the unit off and let is slowly burn itself out, also in all the strange noise of that wild fire, it puffed back from under the door where the airwash gap is and I got a puff of smoke in the room. After it shut down my firebox looked like those photos above, with black soot everywhere. I notice upon cleaning the firepot that I had a lot more ash caked up in the bottom, and was almost rock hard on the top , so I think what happened was it suddenly formed a hard crust, and the tiny air holes in the bottom may have been blocked which caused the fire to be orange and sooty, but I had no over filling, or abnormal amount of pellets in the burn pot. I did a really good cleaning, and scraped the pot good and turned it back on and it has run fine ever since. Thats when I started dumping the burn pot daily or even twice a day sometimes just to make sure the air holes dont get cut off. A good cleaning seems to have fixed the problem, and I didnt give the Quad time to use its safety features, I shut it down as soon as I saw the fire had totally filled the box and it wasnt getting out fast enough. Needless to say Im not very confident in my Castille insert after reading about the hopper fire, I now have my 2 gallon pump sprayer in the laundry room should my hopper ever start to smoke.


You would think these stove manufacturers would put more than just a couple of safety features on them. I would think there should be a sensor in the chute to shut it down in the event any fire backs up into it, and also a sensor in the hopper itself to sense for fire or smoke in the hopper . They should have an automatic shut down that can shut off all air to the firebox and snuff it out, same with the hopper, it should be sealed air tight in case the pellets in the bottom catch fire.

 

[GVA]

same with the hopper, it should be sealed air tight in case the pellets in the bottom catch fire.

I agree with that........
Quad guys why don't they have the hopper lid sealed?

 

[goathead]

You would think these stove manufacturers would put more than just a couple of safety features on them. I would think there should be a sensor in the chute to shut it down in the event any fire backs up into it, and also a sensor in the hopper itself to sense for fire or smoke in the hopper . They should have an automatic shut down that can shut off all air to the firebox and snuff it out, same with the hopper, it should be sealed air tight in case the pellets in the bottom catch fire.

Actually there is a sensor in the chute that shuts it down in case the fire backs up into it. That tripped on mine, but what I don't know is why I still had a fire in the hopper. My "overfire" snap disk didn't trip so I don't know if maybe that was faulty coupled with my exhaust motor failing that built up so much heat that it just got the hopper hot to the point where it just combusted the pellets. That's what I need to go through and figure out and test everything on the stove to see exactly what failed because I know it's more than one thing.

The hopper being air tight, I read in the manual that there needs to be a vacuum in the hopper for the stove to run otherwise the vacuum switch will trip. Not sure how it's done with the top not being sealed. Maybe the shape of the hopper and the way the pellets sit in there...don't know. I do know that the fire didn't have a lot of air until I started moving the pellets around with the top open. That's when it really flared up.

 

[stoveguy13]

the reason that the stoves got a hopper fire is from dirtty stoves ther stove is not getting enough air and keeps feedding but can not keep up with the feed rate the the vacum switch is more for the pipe end of things the nuber 3 snap is in place to shut the stove down when the auger tube heates as when the pellets back up the drop tube

 

[kbjelka]

looking at the second picture (assuming nothing was touched prior to the shot) i'd say the exhaust blower failed and the stove fed for a time before it stopped feeding, thats likley where the ash around the chute came from ,the pot would have piled up and fuel would have nowhere to go, combine that with possible negative pressure (does the instert have an oak?) or an at least partially stopped up flue. smoke is pulled or forced up the chute from the lack of exhaust allowing positive pressure to build in the front of the stove, heat and all, cooks the pellets all the way back , usually a sealed feed system and hopper will help to keep this from happening, also the stove should have had a trip switch of some sort that would have killed the auger as soon as the exhaust blower stopped. if this stove is so equipped i'd take a look at that particular sensor as well assuming it didnt trip and stop the auger from continuing to feed.

burnbacks arent common , usually it takes more than one component failing to cause this usually exhaust blower being one ,and its monitoring sensor being the other. pellet stoves are rigorously tested to assure that the design can withstand and contain a hopper fire, usually the only thing getting out of the stove is smoke.

i do not really know how the quads are set up to avoid this so i cant point you to a direct part or sensor, but usually the setup is laid out in their tech manual.

hope this helps ya.

The only thing I touched in that picture is the white mark on the fire brick. I gave it a quick scrape to see how thick the soot was. The quads have a vacuum switch as well which should trip if the exhaust stops so I'm wondering if the vacuum switch failed also? I might bring it up to the place I bought it and have them take a look at it. I have to totally disassemble it to clean it thoroughly anyhow.

For the other poster, The stove is either 4 or 5 years old so unfortunately it's out of warranty.

Hey GoatHead,

The top baffle plate looks like it is out of position. If the photo is untouched then that may have been your issue. It should be all the way to the right with the tab on the lower right nested in the notch. Check that you are installing the baffle plate correctly. If it is installed wrong the hopper floor can get very hot.

 

[kbjelka]

Scans, not the best quality, let me know if anyone wants them email or pm'd.

Hey GotzTheHotz I would love a copy of that PDF. Can you send it via PM? Thanks!

 

[goathead]

Hey GoatHead,

The top baffle plate looks like it is out of position. If the photo is untouched then that may have been your issue. It should be all the way to the right with the tab on the lower right nested in the notch. Check that you are installing the baffle plate correctly. If it is installed wrong the hopper floor can get very hot.

I double checked that and the baffle plate is sitting in the tab like it should. Whenever I clean the stove I make sure that it goes in right because I always have to pull down a bit for the tab to go in. I haven't taken it apart yet because I want the dealer to see it as it sits. The only thing I pulled out was the auger because I wanted to make sure that I had all pellets out. The auger motor appears to be seized also. Something else to fix.

 

[Czech]

Looks familiar. The baffle is offset on the inserts, that is normal. Buff the auger, get the upgrade airflow, go from there. I'm installing the kit Monday at my mom's, I'll keep the page posted.

 

[richg]

I hate to be the bearer of bad news, but with a siezed auger motor, blower and overall system failure, have you considered junking the stove? I know it wasn't cheap, and a new one will be big bucks as well, but is it worth your safety?