Hopper Fire, Alaska Channing 3

Xmas eve, dealers closed including Alaska, so I am turning to the experts.
I am in my fifth heating season with my Channing 3. Direct vent. no baro damper. have manameter ,but it is not permanently hooked up to stove.No major problems until now.
Last night I noticed fire had backed up into the hopper. Caught it relatively early. No damage done. Very scary though as we were about to go to bed. Shutdown stove immediately. Still down!
Stove running since Thanksgiving. Glass replaced and both door gaskets replaced prior to startup.
I felt stove was running well up to this point. Ash production, coal consumption lower than in previous years.
Other observations include: my bagged Reading rice coal is dripping wet coming out of the bag, never seen it so wet.
Hopper was 90% full. I never let it get below 50% for fear of hopper fire.
It's been very warm recently here in R.I., sixty degrees . Stove has not been working hard.
From reading on this site , some would suggest I had a failure of the grate gasket.

Looking for any and all help from the experts.
Thanks!

I'm no expert on hoppers but I've read they need to be completely sealed so fresh air can't leak into them. The fire follows the air source. I'm sure an expert will chime in for you

Check gaskets as you mentioned.

Also, check exhaust system/pipe for ash build up. A recent thread had exhaust heading into the hopper and it was due to less chimney draft because of ash in the flue pipe.

Agreed, if the air being pumped by the combustion fan exceeds the gases being removed by the direct vent or natural draft the firebox becomes positive, or pressurized. The gases have to go somewhere. Up into the hopper it goes, possibly taking the fire along with it.
When you say "direct vent" do you mean you are using a direct vent fan in the stove pipe or a power vent mounted outside the structure? Either way the pipes and unit need periodic cleaning in order to function properly.

When I had the Alaska stove (connected to a chimney) I didn't have a lid on the hopper, only had an issue once on a warm day after a cold night when the chimney lost draft. You don't need a lid on the hopper if the stove has the correct amount of draft...all the time.

It would be a good idea to leave the manometer connected all the time, that way you can see what the draft is doing and respond accordingly.

I will check stove pipe, however stove and pipe were cleaned very well during spring shutdown. I have not even run one half of a ton yet.

My Chimney has marginal draft the warm weather along with the weather patterns like - inversion layers and changing barometric pressure drove me crazy keeping the old shaker stove in the shop running but the Harman pulled thru fine Id bet you just bad chimney effects.

give stove a good cleaning, empty hopper to make sure all is ok.... Wet coal can cause havoc, I recommend to let coal bags drain into a catch pan before dumping into hopper. I've been having allot more fly ash this year so I'm cleaning out stove pipes more often then before.

Thank you. I store my bags in detached garage. Once a week I empty bags into five gallon pails for storage in my basement.

glennl wrote:Thank you. I store my bags in detached garage. Once a week I empty bags into five gallon pails for storage in my basement.

place some holes in bucket, then you'll be able to place buckets on blocks inside of tote and water will be captured in tote... Dry coal

Check your PM. The only real solution is to install a barometric damper between the stove outlet and your exhaust fan. As you know I have a Channing 3 and had two hopper fires. The barometric damper took care of this problem. If the stove needs to pull air it can get it from the damper instead of through the lid or bad seal. You can use your Manometer to properly dial in the damper. Good luck. Was there any damage done?

Still wanna know if it is a direct vent with a fan inside the structure or a power vent on the outside of the building.

traderfjp wrote:Check your PM. The only real solution is to install a barometric damper between the stove outlet and your exhaust fan. As you know I have a Channing 3 and had two hopper fires. The barometric damper took care of this problem. If the stove needs to pull air it can get it from the damper instead of through the lid or bad seal. You can use your Manometer to properly dial in the damper. Good luck. Was there any damage done?

Huh? How will the stove pull air through the baro? I'm confused!

lewis wrote:My Chimney has marginal draft the warm weather along with the weather patterns like - inversion layers and changing barometric pressure drove me crazy keeping the old shaker stove in the shop running but the Harman pulled thru fine Id bet you just bad chimney effects.

His stoker is not connected to a chimney, should not be affected by weather and pressure changes like that.

Not trying to be a PIA here but I get confused easily.

Thanks to all for responding. Direct vent attached to stove, not outside of house.

Trader, no damage done, although I have not emptied hopper yet. I believe I caught it very early.
Grate had burning coals as usual , but I just happened to notice a glow from back where the feed paddle is. I took my stove shovel and dragged it all forward until I could see no more red coals in paddle area. Then I shut stove down.

That's what I thought. Make sure the pipes are clear, the fan blades are clean, and the fan motor is working correctly. If you install a baro damper it goes between the fan and the stove. Manometer connection between the baro and the stove. Do you have a speed control on the fan?

I trust you have one or more working Carbon Monoxide detectors in the house.

I have four carbon monoxide detectors. Two within 15 ft. Of stove. One has a digital readout which never moved from zero.

Nobody has mentioned the grate gasket.
Am I wrong to think this might be the problem?