Quadra-fire Mt Vernon Sparks coming from heating tubes

[Jimteacher]

I have an original... old version... of a Quadra-Fire Mt Vernon.
...used for many years.
...have replaced both fans and gasket around pot...(though that's deteriorated).
At the end of last year, I started getting sparks coming out of heat pipes coming out into room.
VERY dangerous, and nothing will stop them as them come out. Screens don't work.
So... sparks coming from combustion chamber and getting into the air circulation system!
How do they get there? Some connection to air circulation fan and combustion system?
Could this be coming from a bad gasket around the combustion pot? That's bad.
I don't know of any other connection between air heating and combustion chamber.
Thanks for your help, as this is very scary!
jim

 

[johneh]

If you are truly getting combustion sparks and gasses into your circulation
(heat exchanger ) shut that dangerous stove off and keep it off until you
find the hole in the heat exchanger. You are putting your family's lives at risk!

 

[Jimteacher]

anIf you are truly getting combustion sparks and gasses into your circulation
(heat exchanger ) shut that dangerous stove off and keep it off until you
find the hole in the heat exchanger. You are putting your family's lives at risk!

I don't have it on yet this year, and won't put it on until I can find where the sparks come from. As it's an old stove, the dealer doesn't know about the path of stuff. I'm going to try a bright light in different places, but I thought someone might know the air path so I could figure out where to look.
The gasket around the combustion pot is messed up. I don't know if that would be a path, but I don't think the combustion pot is connected to the heat exchanger.

 

[Mt Bob]

Well first things first, remove back of stove,if it has one, and see if there is any way pellets are escaping the auger or hopper, that could fall on something hot, then into the room blower. Or even from burn area. If not, buying a few HVAC duct work "smoke bombs" could help you.

 

[Jimteacher]

Well first things first, remove back of stove,if it has one, and see if there is any way pellets are escaping the auger or hopper, that could fall on something hot, then into the room blower. Or even from burn area. If not, buying a few HVAC duct work "smoke bombs" could help you.

Thanks for the suggestion.
In the quadra-fire, the fan is on the bottom to circulate into the heat exchanger. I'll take that off and see if there are any openings there.
The pellet auger is pretty tight... goes right into the burn pot, but air is blowing into the pot from the bottom, and goes around to the right side of the combustion chamber, where a fan, which I replaced recently, blows it up the chimney, I think.
There might be some connection to the heat exchanger back behind the combustion chamber.
I'll have to try a smoke bomb. I was going to try a bright light as well.
Tiny fast, moving sparks were coming out of the heat exchanger...too small to be stopped by a screen even.
I'm attaching diagrams of the guts of the stove.
I'm an English teacher, so I'm not too hot at diagrams...
Thanks for your help...
jim

 

[Mt Bob]

Yes, it is probably a bad/rusted out heat exchanger, but doesn't hurt to cover all the bases. I doubt a replacement is available, and doubt it is a gasket. To actually see sparks, raw pellets have to be getting into the exchanger tubes, or, fresh sparks/chunks are being sucked in, right from firebox. You also might be able to tell by using a vacuum cleaner on blow, and blowing into the exchanger tubes.
Good luck.

 

[Jimteacher]

Yes, it is probably a bad/rusted out heat exchanger, but doesn't hurt to cover all the bases. I doubt a replacement is available, and doubt it is a gasket. To actually see sparks, raw pellets have to be getting into the exchanger tubes, or, fresh sparks/chunks are being sucked in, right from firebox. You also might be able to tell by using a vacuum cleaner on blow, and blowing into the exchanger tubes.
Good luck.

Thanks! ...I'll try the vacuum cleaner... I have a leaf blower that might do it as well.
I won't have time to play with it until the weekend.
I'll let you know what I found out.
Have a great day!

 

[Mt Bob]

Oh, slight possibility dirt and crap got into the tubes, forced by the blower, and stove is fine. Sometimes even mice, but usually cat hair.
Realistically, if is wood pellets, you should be smelling them burn,also. Perhaps just tubes need cleaned.

 

[Jimteacher]

Oh, slight possibility dirt and crap got into the tubes, forced by the blower, and stove is fine. Sometimes even mice, but usually cat hair.
Realistically, if is wood pellets, you should be smelling them burn,also. Perhaps just tubes need cleaned.

...maybe reverse blowing might show that... ...had ti 20 years, without cleaning that part...

 

[Mt Bob]

Yep, we used to run a brush down them, vacuum and blow with air.

 

[Jimteacher]

Yep, we used to run a brush down them, vacuum and blow with air.

Thanks...

 

[tbear853]

If sparkling embers are coming into the room, there's holes somewhere.

 

[3650]

If I remember correctly on my old quad the heat exchanger tubes are aluminum. Perhaps one cracked or split.

 

[Mt Bob]

If I remember correctly on my old quad the heat exchanger tubes are aluminum. Perhaps one cracked or split.

Or the tubes would come loose up at the top, but could be repaired.

 

[tbear853]

Aluminum heat exchanger parts exposed to burn products?

 

[3650]

I believe there is a heat shield in between the flame and the tubes so they aren’t directly exposed. It’s been 15 years so my memory is a little rusty but this is what I recall. I remember putting a magnet in one and it not grabbing anything. Maybe they were stainless. I just know they didn’t have any carbon in them.

 

[Jimteacher]

Well first things first, remove back of stove,if it has one, and see if there is any way pellets are escaping the auger or hopper, that could fall on something hot, then into the room blower. Or even from burn area. If not, buying a few HVAC duct work "smoke bombs" could help you.

I went down and got under and around everything. The air path goes from the fan which blows the smoke up the chimney, and also sucks the air through the holes in the the pot. ...fan sucks air through pot and then out to chimney. Squirrel fan right under the stove (which is right next to the hole where air goes to the bottom of the pot) pushes air through the pipes, which appear to be thick and strong. So... sparks are somehow getting into the pipes.
My son says it's a positive-pressure / negative-pressure thing, with evidently something allowing sparks to get into the squirrel cage fan and blowing them into the pipes.
ONE possible thing... The gasket around the pot is messed up, so maybe enough air isn't being drawn through the holes in the burn pot because the gasket under the pot is defective. ...ie less pressure to pull fire / smoke into the chimney pipe.
I ordered a gasket to check. My son says to look under the pot while the fire is going on to see if sparks are going out next to the squirrel fan, which might pick them up and blow them through the heat pipes.
I don't see any other path for sparks under pressure.
What do you think?

 

[Edrrt]

I went down and got under and around everything. The air path goes from the fan which blows the smoke up the chimney, and also sucks the air through the holes in the the pot. ...fan sucks air through pot and then out to chimney. Squirrel fan right under the stove (which is right next to the hole where air goes to the bottom of the pot) pushes air through the pipes, which appear to be thick and strong. So... sparks are somehow getting into the pipes.
My son says it's a positive-pressure / negative-pressure thing, with evidently something allowing sparks to get into the squirrel cage fan and blowing them into the pipes.
ONE possible thing... The gasket around the pot is messed up, so maybe enough air isn't being drawn through the holes in the burn pot because the gasket under the pot is defective. ...ie less pressure to pull fire / smoke into the chimney pipe.
I ordered a gasket to check. My son says to look under the pot while the fire is going on to see if sparks are going out next to the squirrel fan, which might pick them up and blow them through the heat pipes.
I don't see any other path for sparks under pressure.
What do you think?

Did you remove all of the metal for the firebox. The two side panels and the roof panel? That'll expose the heat exchanger tubes so that you can see them. My guess is that there's an opening somewhere along the path in there.

 

[Jimteacher]

Did you remove all of the metal for the firebox. The two side panels and the roof panel? That'll expose the heat exchanger tubes so that you can see them. My guess is that there's an opening somewhere along the path in there.

I've got them off... Tubes look OK from the outside... thick and solid. Nice and smooth.
I'm putting in a new gasket tomorrow to see if that helps. If not... gotta find a hole somewhere.

 

[Edrrt]

I've got them off... Tubes look OK from the outside... thick and solid. Nice and smooth.
I'm putting in a new gasket tomorrow to see if that helps. If not... gotta find a hole somewhere.

I mean this sounds super bizarre.

You're exhaust fan should keep negative pressure coming through the cold air intake which is a little square in the lower right hand corner, then up through the fire pot, and then through the baffles and up your flu.

You have sensor that ensure is that there is negative pressure continuously being pulled on the firebox.

It shouldn't be possible for air to be going in the other direction. And even if it did and you had sparks that came down into the ash pan, there still shouldn't be anyway for it to get out the back where it could be picked up by your convection blower.

Did you open the side and look at the seals on the exhaust blower?

It would also be quite strange for you to be getting embers blowing out of your heat exchanger tubes but no smoke in the room?

How would that be possible?

I'm wondering if you didn't just have some dust or flakes of something that got ingested and heated up to the point that they could combust while in the tubes?

 

[3650]

Only way I see it happening is from the confection fan or some kind of electrical shorting sparking and getting suck into the air intake. That would have to be some serious sparking to travel that path and still be ignited with all that turbulence if the pathway.

 

[Mt Bob]

The burn pot gasket has nothing to do with problem.
It would be dangerous for any stove to be built where a simple gasket separated exhaust from convection air.
"Tubes look OK" means nothing. You must disassemble stove, as for doing a deep clean, clean, then try to move,wiggle rattle tubes, as said, they are swedged in, and known to get loose at the upper ends.
Did you clean the inside of the tubes, and the room air pathways? Doesn't sound like it.

 

[Jimteacher]

Thanks for your advice!
I took everything apart.
The tubes are clean, and are welded... not loose. and look really solid inside.
I don't see any connection between tubes and the combustion chamber and air, except that the air intake for the combustion chamber is right next to the squirrel cage fan that goes to the tubes.

The gasket around the the pot was shredded, so I put a new one in.
I vacuumed everything out.

Then I very carefully started up the stove and sat right in front of it until everything came on ... 20 minutes or so for fan through tubes.
No sparks at that time.
I turned it off and will try again tonight or tomorrow.
Maybe cleaning / disassembling everything did something.

The cast iron right below where the the pellets come in...the back plate...was broken, so I suppose some sparks could be sucked in behind the back plate.
I put a piece of angle iron to cover the hole. I still don't see any connection to the tubes, though the tubes are right above the back plate.
Maybe that has something to do with it, as instead of the sparks, exhaust, going out through the right side of the chamber, they may be sucked into that hole right behind the pot, which goes up next to the tubes.

I'll close the broken spot more fully.
Here's a picture of the hole right above pot...which I put an angle iron in to close.
Thanks again...

 

[Edrrt]

How did that get broken? That shouldn't make any difference, it just opens into the heat exchanger back there, sparks normally are pulled in there.

I'm wondering if you really had sparks coming out of your heat exchanger tubes or if some dust came off your blower and faked you out in the lighting or something?

If you had sparks flying out... You'd have all the exhaust glasses/ smoke too. There's not a lot of ember's in a pellet stove compared to the mouth of smoke/ gasses. Your room would be filled with pellet stove exhaust immediately if it was venting ember's out the exchanger tubes.

What exactly did you see? Are you sure? And was there detectable smoke/ odor in the room with this event?

I think we all want to know if this is real what's going on because it could be a safety flaw that affects all of us.

But this doesn't seem possible based on the physics?

 

[Mt Bob]

Starting to look more like just crap from inside the tubes. Yes, they can get that hot. Bugs, spiders, pet hair,etc.
The burn pot gasket will keep stove running properly, it is a maintenance item.
A long hot fire, where everything expands, should be a good test for you,