Keystoker Koker HELP!!

Arrived home from work today and noticed a different burning smell.. Found that the fire in my furnace had burned it way into the coal hopper.. I have gotten the fire stopped and now waiting for it to cool down. I did remove the stove pipe and removed a good amount of fly ash.. ANY info would be GREATLY appreciated. I have the manual that came with the unit, but it is very hard to view..

Thanks,
John

Not a expert, but from what I read, hopper fires are usually caused by poor draft.

Clean the stove, clean the connector, check the chimney for blockage. I have a small mirror I stick in the chimney and angle up. If i see light in the shape of the chimney with sharp edges, I know it is clean with no blockage.

Reassemble everything and check your draft with a manometer before restarting. After restarting, check/adjust your draft accordingly.

Others may have some tips on this also.

Direct vent or Natural Draft chimney? Yes, ash build up will decrease your draft.

FIRST, have you set your draft correctly with a draft gauge? Do you have a working CO ALARM?

You have poor draft and/or a gasket leak under the grates, They need to be sealed good. Check everything first.

either increase your burn a bit, turn up your idle, cover your baro damper to help increase the draft, if you have CoalTrol, bump up the MIN settings.

John3, how did you make out?

Couple of points learned here. The grates on the stoker need to be sealed properly with furnace cement. If not, uncontrolled air
may enter causing the burn area to reach into hopper. Remember seeing issues with a power/direct vent not properly adjusted
causing a hopper fire as well.

I though an OVER draft (too strong) caused hopper fires not LOW (too weak) draft! Which is correct? Thanks

Hopper fires occur in general when air is drawn through the hopper.
I am not an expert in this - keep in mind an expert is a person who has made every mistake in a narrow field.

I was at a fire call a few weeks ago with a pellet stove fire. The fire had traveled up through the worm feed into the hopper. When we pulled the stove vent cap off, the flue was over 1/2 filled with ash. With the vent partially blocked, combustion gasses traveled up the fuel feed and into the hopper.

AHS units have a warning on their hopper to keep the lid on during operation. The reason is with the power draft fan, it can created enough draft to suck air through the hopper, causing the fire to travel up the coal feed like a lit cigar.

So, it depends on how you look at it. Bottom line is the hopper must be dead air (dense enough to prevent air movement) and the flue must be of proper draft - not too strong, not too weak.

Depending on the model and type of stove you have, a hopper fire could be caused by improper draft or operation - either too strong - sucking air through the hopper, or too weak - allowing combustion gasses leak back through the hopper.

jrn8265 wrote:I though an OVER draft (too strong) caused hopper fires not LOW (too weak) draft! Which is correct? Thanks

I think on coal it is an overdraft.

The scenario Steamup gave would work for pellets which will ignite at a lower temp. I am pretty sure with a coal stoker the only two ways you could get a hopper fire is too much draft, or an improperly sealed grate.


I am no expert either, just my opinion.


Eric

A low level of coal in the hopper, allowing air to be drawn through the hopper, a hopper that has rust holes in the base or the base of the hopper is not fitting the top of the stoker feed correctly, . Any of these will allow air to be pulled through the hopper and the fire will follow the air.

Greg L

Could it be too many fines clogging up the holes in the plates? By far a novice myself but just a thought since I have a koker myself.

On a stoker you have to remember that there is a combustion blower running at all times blowing air into that firebox. If you have a pipe filled with fly ash or a very lazy chimney (more than likely the stove is on an idol to low burn not producing enough heat in the chimeny to give a good draft) then if you add a possible wind down draft, that combustion blower is going to push air out of the stove where ever it can (the hopper). So a hopper fire can happen on both an over draft as well as not enough draft. Low stack temps in milder weather is not always a good thing.

Not sure if you got this fixed but I have had the same issue twice this season. My final outcome is as follows: Service call after second cam replacement found the draft was Pegging the draft gauge. Draft was set only to have the stove stink us out the following day apparently I missed some fly ash in my cleaning of my exhaust pipe and the gasket on my direct vent was sucking air. Keystoker suggested after cleaning unit i would not need to re-silicone the direct vent motor in the unit. I would suggest sealing this as any thing can suck air or puff smoke. Well so far so good this time however since regasketing and cleaning the exhaust I am not getting a clear draft setting. seems to be bouncing around a bit need to find out when to set the draft. under heavy burn or at idle. Good luck with your stove this site is great

You should always set it at FULL BURN around .04 on the draft gauge so it can handle exhausting the fumes easily. A power vent should have a steady draft on the stove. It should not bounce around .

Low fuel level as Greg said. Gearbox issue so pusher block does not move properly, damaged pusher block, arms or shaft. Incorrectly set or damaged feed slider, ash pan overfull, no place to dump....

Bet this got your attention! Look around the feed mechanism and arms to see if you can find the issue. Gaskets OK? Blower flap left wide open? Lots of possibilities!