Hopper fire!

I have an older alaskan with a rehrostat feed control. I just recently got it and still learning. Last night before i left my place I turned the rehrostat down since i wasn't going to be there. This morning when I came home the main burning channel was out but the coal in the hopper was on fire!!! What did I do wrong?

Burning anthracite will follow the air source. How much coal was in the hopper? It needs to be at least 1/2 full.
Also, on my Koker, if the gasket around the stoker unit was to begin leaking air, the coal would follow the air source back under the hopper. Your Alaska may be the same.
If you had a sufficient amount of coal in the hopper, it sounds like you may have a problem that needs to be addressed immediately.
I suspect shutting down and reconditioning the unit is in order.

Gasket leaks, or improper draft can cause hopper fires. Time for a teardown.

I'd run with gaskets first--when did you last replace them?

I bought the stove and the guy said it was good to go. When I run it full blast it runs perfect! I had it dialed back before but never this much. Maybe I had it turned down to low.

Been there done that. Replace the strong back gasket on the feeder or better yet all the gaskets and seal the back with furnace cement. The cement part is not in the manual, sort of belt and suspenders but it helps me sleep at night. Make sure the cement is smooth or coal will not flow. If you get air flowing back there the fire will burn too far back. When you moved the stove you probably removed the feeder or at least jostled it around a bit and now the gasket is not seated properly. The strong back gasket is the smallest, easies to damage and most expensive of all the gaskets. Also check the gasket on the coal bin and make sure it is not letting air in. Also do not let the bin get too empty. Another word of caution, my rheostat failed on Monday and my stove ran away because the stoker ran continuously. I caught the situation because the house temp went to 80 in a short time. I installed a Coal-Trol on Tuesday. I was luck enough to get a hold of them before they shipped for the day and it was here the following afternoon. It shuts down at 98 degrees which I wish was adjustable but at least it shuts down.


From the manual

FEEDER ASSEMBLY
Locate unit (See Fig. 1 on page 3 and Fig. 2 on page 2).
Check that strongback gasket is positioned properly as
shown in Fig 1. The strongback gasket position is critical
in that it prevents air escape to the hopper area which
could result in “hopper fire” or warpage to the overplate.

If you did not get one here it is

http://www.produitsjl.com/pdf/kast_console.pdf

Are you using a Barometric damper?

Flyer5: My set up has my pipe on an angle so I can't use one(Barometric d). I use a power vent. I feel that I just had the rehrostat to low. Maybe?

keithkeystokerefm wrote:Flyer5: My set up has my pipe on an angle so I can't use one(Barometric d). I use a power vent. I feel that I just had the rehrostat to low. Maybe?

There's your problem . You need to have a baro and have it properly set. Too much draft and or not enough will cause this. Most of the time too much.

Flyer5 is right . Your power vent fan is probably sucking air out faster than your combustion fan is putting it in the stove. The fire followed the air. Sounds like feed ramp gasket or a hopper gasket is leaking air. You should also have a draft regulator, it would help from sucking the air thru the stove. Check the draft once installed.

I have a power vent set to minimum it still pulls the barro in about 15% for .03WC. If I did not have a barro I would guess my draft would be at least .1 WC. I have to hold the damper shut and see . Get a barro before you do anything but I would still cement the back of the grate.

So i replaced the hopper gaskets and even used puddy. I had the feed rate set pretty good and had almost a full hopper of coal. When I came back this morning the fire was still burning in the fire ramp/ channel but the the hopper was on fire! Whats going on? Is my lack of a baro damp. the root of all my problems?

keithkeystokerefm wrote:So i replaced the hopper gaskets and even used puddy. I had the feed rate set pretty good and had almost a full hopper of coal. When I came back this morning the fire was still burning in the fire ramp/ channel but the the hopper was on fire! Whats going on? Is my lack of a baro damp. the root of all my problems?

YES. You need a manometer to determine the proper setting for the power vent and baro damper. You are pulling too much draft !!!!

You can get a Dwyer Model 25 from Graingers or ebay. That is what most of us use to check the draft.

Then install the baro. You just have to make sure that the swivel pins for the baro are plumb and level. Doesn't matter if your pipe is on an incline or not.

Now adjust the power vent and baro together to get the proper draft reading. THEN you should be all set.




Rick

While I haven't gotten a hopper fire yet, I have had an occassion with CO into the house, setting off alarms on all 3 floors.

Happened when the outside temps were above 50 or so and I had dialed back the reostat to about 1.5 on the dial. Only a very small flame at that level. Problem is my 60+ year old brick chimney apparently doesn't vent too well. Last season, when it warmed up, I simply put tin foil over the baro and taped it. Solved the problem in my case.

Baro 100% for SURE! I will say this is not a new problem with the Alaskan though and maybe thats why the seller sold it to you? One example here for you to learn some more : Hopper Fire - Alaska Channing 3 with direct vent