Hopper Fire - Alaska Channing 3 With Direct Vent

reicharb wrote:Has anyone seen this happen with a Harman Magnum?

Because of the design of the Harman Verti Flo stoker system and the movement of the Pusher Block, I think they are the least likely to have something like this occur .

Hi e.alleg, well to start, I thought I was only going to have that waste-oil burner for a month or two, the owner paid me to run it and fix it for him. It was not working correctly. [It was all clogged up from poor maintenance]

So I didn't want to cut a hole in the ceiling, and the roof and shingles, and have to buy a 8-10' long piece of insulated pipe, deal with the sealing of the shingles etc. The sides of the barn style roof are very steep, like a 12/2 pitch, the upper flatter section is about the opposite, about a 3/12 pitch. To get into the 3/12 pitch area and away from the corner or pitch break reqired the chimney to be about 3'-4' away from the inside wall and this was awkward too.

So I had the short section of insulated to go horizontally through the wall, it was free, the wall is a single thickness of plywood, the piping inside free and easy to temporarily rig up. for just a month or two. And if I needed more draft, I could add an elbow and 8' of vertical pipe in a few minutes. And once the heater was fixed, I could just cover the hole with the plywood plug I removed, and caulk it in place. I have it ready to insert in the hole, with a backer board, but...

The waste oil heater is still here, the owner doesn't seem motivated to come get it, even though he doesn't owe any more money, so I'm burning ATF from my sideline autotrans bussiness in it. The coal stoves came along, and I wanted to run them before I offered them for sale, not wanting to sell something with an issue., so I hooked up to the only available chimney flue. So the temporary waste-oil chimney became a coal stove chimney.

And so I still have the 'temporary' chimney in place, with no desire to cut holes in my insulated ceiling and shingles, or try to seal a chimney to the odd roof pitches. If I do anything I will add an elbow and some vertical to the pipe and make it look a bit more respectable.

I showed this chimney here to point out that with the worst possible chimney my LeisureLine stove would not get a hopper fire. It is embarassing to show such a hack-job chimney, but sometimes it illustrates what needs to be said. This is a shop, with lots of infiltration and not a lived-in space. I'd never burn anything attached to that chimney in a living space.

I think that explains the 'temporary' chimney. I may even buy some chimney block an put in a masonry chimney if I decide to keep the coal stove. The floor is heated to 50* from my big boiler, so I'm not in bad need of shop heat. The shop is actually pretty comfortable.

Greg L

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Ok now I understand. I had a waste oil furnace I picked up but it was a homemade job from the 50's, I gave it to a guy who uses it all the time. It is basically a used propane cylinder with a hole cut in it for the burner which looks almost exactly like a fuel oil burner but with bigger nozzles. My neighbior has one that was for home use, it utilizes a very exact "drip" system. lol. Really, you fill the resevoir with kerosene/waste oil mixture and it drips oil onto a fire. It scares me but they use it in the shop and it seems to work. It looks like an old radio cabinet with the faux woodgrain plastic trim. Every garage I ever worked in had a waste oil heater mounted on the cieling but none of them ever worked right.

Finally I figured out how to solve the hopper fire problem I have been encountering, and here are the steps to see if the cause of the fire were the same as in my case.

This is for an Alaska stove:

The fire was so bad it was burning at the buttom of the hopper, you can see in this picture the damage it caused,Just take the hopper out, turn the motor on, and see if air escaping by looking for flying dust/ashes around the push bar (Carpet ).

The front grate is easily removable on the Alaska stoker stoves, it's even easier if the carpet is out of the way, when removing the grate, you'll notice that there is no seal rope at the back section, your only hope that both sides ( grate and holder ) have smoth even surfaces, in my case, there was a left over weld dot on the back surface, you can see it in the picture, it prevented the surfaces from contacting each other for a complete seal , I guess the quality inspection team at the Alaska factory did not notice it, I notched it out with a hammer and a knife.

Just clean the surfaces, apply a stove cement on the grate back surface and put it back, look at the pictures I have.

by the time you put back the hopper in place, the cement would be ready for the stoker to be fired up, and you'll notice the new rectangular shape of the fire.

Hi GeorgiePorgie, welcome to the forum.. Sealing up the stoker is important,, any air leaks upstream of the holes in the grate will support combustion where you don't want it.
If your draft is too strong, it will pull air through the hopper and around the pusher. Set your barometric damper [if installed] with a manometer.. or set the over the fire [inside the firebox] draft with a manometer, using a reostat to regulate the direct vent motor speed..

On many if not most flat bed stokers there is a thin, flat gasket at the back of the carpet. This gasket has a wire reinforcement, the gasket is called a 'hardback' if I remember correctly. Often there is welding 'spatter' or flakey rust that takes up the space needed for the gasket. Using a thick application of furnace cement works well as a gasket substitute.

Greg L

not sure if anyone is still reading this thred but the alaska I got just did the same thing. I looked in the hopper that was near empty and seen a few gloing coals. thinking it would push down I added 50# then I was looking for what was causing the smell 1 hour later then after 3 hours it showed up peeking through 50# of coal. my stove also has the direct vent system.

Blue Chopper, when was the last time the gaskets were replaced on the coal feed side.? I also have an Alaska 3, in its 3rd year of burning and plan to replace all gaskets this year.

I just got the stove a month ago used but I changed that gasket before I installed it. just don't let the coal run low in the hopper and its fine.

If you are getting hopper fires its most likely from your backpressure switch not being set right. You need the precise equipment to do this. It takes the service man about 3 minutes , the short of it is the air is being restricted and backing up the coal chute.

Without a barometric dampner or a variable setting on the exhaust I'm not sure how you can set the back pressure. I have both on my stove and can dial everything in perfectly. When I first bought my stove I had two fires. I spoke to a guy who was selling and making stoves for over 30 years. He explained everything to me and said that he would never sell a stove without a barometric dampner. If the draft gets too strong the air gets pulled in from the room and not from the hopper.

Inspector911 wrote:If you are getting hopper fires its most likely from your backpressure switch not being set right. You need the precise equipment to do this. It takes the service man about 3 minutes , the short of it is the air is being restricted and backing up the coal chute.

I just had a new Alaska Channing 3 with direct vent installed recently. Does anyone know if this is still an issue with this stove. I asked during the installation what prevents a fire in the hopper and they said because there is no combustion air.

CrazyHorse wrote:I just had a new Alaska Channing 3 with direct vent installed recently. Does anyone know if this is still an issue with this stove. I asked during the installation what prevents a fire in the hopper and they said because there is no combustion air.

Welcome to the forum, the issue is common with any stove that has a flat grate, its almost always caused by a bad strong back gasket, this is the gasket that seals between the grate and hopper area. Seeing as yours is new its a non issue but alaska does recommend you replace grate gaskets every 3 years to prevent such things. These stoves are very easy to work on so its really no problem doing your own work, use the search up top the forum and search for channing III and you'll find info on servicing these. You can also start a thread in the stokers section of the forum and ask away

By the way this is a very old thread that discusses a carpet feed yours is the newer paddle feed so although the grate gaskets are similar the feed system is totally different so don't go by some of the things mentioned here

Thanks for your response, I feel better about it. I am still gonna make sure the hopper stays full. So far I really like the stove although it is a little louder than I thought it would be