Moisture in hopper/co2 alarm going off

Hello folks!!

We’ve been burning an Alaska Stoker 2 stove for a month or so now with no issues. Wednesdag morning we woke up with a bunch of moisture in the hopper, turned the stove up a little and it went away. Thursday morning we woke up around 4am to hear the co2 detector going off and the hopper full of moisture yet again.
We vacuumed out the stove and the pipe as Alaska and a few people I asked said the fine ash buildup in the pipe could have caused the issue. Fired it back up yesterday afternoon and it did great most of the day into the night, no moisture in the hopper. But this morning shortly after 6 the co2 alarm was going off again with moisture in the hopper.

We’ve burned this stove since the beginning of February with no issues. Literally NOTHING has changed. It’s the same bagged coal we’ve been burning since the start, we haven’t even gone through a ton yet.

Any ideas? The only thing I can think of is the barometric dampener needs fine tuned and I don’t know how to do it...

Need stove and pipe system throughly cleaned of accumulated flyash. Any horizontal surface can over time pile of fly ash...worse it gets the quicker it collects till moisture and CO starts spilling out.

Manometer gauge is required to calibrate barometric damper. This will also show you draft changes over time.

Excessive combustion fan likewise will cause positive draft with symptoms same as you are seeing.

McGiever wrote: ↑

Fri. Mar. 08, 2019 9:17 am

Need stove and pipe system throughly cleaned of accumulated flyash.

We just vacuumed out the stove & pipe yesterday after I talked to Alaska and they suggested this... We’ve only been burning this a month yesterday. Could that still be the issue?

Well, not so much if done effectly.

Here is another common cause...your system has reduced draft capability.

Could be baro set too low or some other opening in system is not sealed or closed as should be.
Clean out door on chimney must be closed and not leaking and reducing draft.

Search here...top right of this page...
For Dwyer MK II ...for manometer details

Will double check clean out to make sure that’s fine. There was barely any ash in the pipe but I vacced it out anyways. Other than that, I don’t even know where to start. The baro dampener wasn’t messed with since the start

You must also inspect and clean the chimney, if needed. Check that any cleanout door is closed and well sealed.

The combustion fan is blowing in more air than the draft can exhaust. So it backs up. The baro flap should be closed with that condition.

Bird or some other dead critter in chimney.
You could always hire a chimney sweep to do inspection and cleaning if not comfortable accessing from roof.

Since you are new to coal at one month of use this makes for a potential situation not normal to the conventional coal burning issues.

Chimneys that were changed over recently from years of wood burning use can have creasote curling and separating in small sheets from liner walls which do fall off and accumulate at lowest part of chimney and at the thimble collar causing a growing blockage.
This may require a concerted inspection to diagnose and remedy or clear such a growing blockage.

Clean out door is fine, maybe two small wood stove shovels full of ash yet, that’s it. I just pulled the stove out from the wall to make sure that horizontal pipe was clear and there’s MAYBE 1/4” of ash on it so I very highly doubt that’s the issue and that’s about how much was on the bottom of the pipe too right out of the stove.

Is the baro flapper closed and what is going on above the stove pipe in the chimney- is is clear?

It's sounding more and more like too much air input by combustion fan...try closing off fans intake screen some to not flood the firebox with air and making positive pressure...common denominator is chimney changes cannot always keep up with air being fed in...trim it back a bit.
If no swing pan to adjust the air intake amount , you could improvise with fridge magnets to partial block the intake area.

A manometer to measure draft is not something frivolous, especially where fans PUSH air into a firebox...this isn't a wood stove

Our bagged coal is stacked right in the same room as the burner! But that’s a good thing to know

I attempted to try to edit the first post but it wouldn’t let me. Here’s some pics of my setup.