Co leaking, possibly from hopper

Newcomer here. Been stalking these forums for a month or so now. Lots of good info so far but nothing that has helped solve my problem so here it is.

I have a keystoker stove that burns rice coal. It came with the house I just bought. Well I fired it up and it ran for about 2 weeks without an issue. Then I got home from work one day and the co detector was going off. I opened all the windows and checked the stove and it was almost out. So I figured I lost my draft and it backfed co into the house. Had the fire dept come up and they saw nothing wrong with the setup. I cleaned the chimney (full of ash). The guy I bought the house from said he cleaned it, obvious lie. Fired it up again the next day, went good for about a week. Co detector at 4:30 in the morning. Got everyone outside and called the fire chief and he cane in and was reading levels on his unit so it’s jot my co detector (I have 3 now btw, being paranoid). Co detector has gone off 2 more times. Once it was going off when I got home from work, went through the routine, and left it running. Digital co was reading 15 ppm. Well about 5 hours later it went off again. I shut the stove down and called a professional. At this point I had redone the door gaskets, cleaned the whole thing out with a shop vac, cleaned the chimney. He came up the next day, redid some of the cement on the feed tray, not that it was bad but as a precaution. He punched the air feed holes on the tray. Disassembled the air feed motor and checked for fine ash in there, wasn’t any I had already cleaned it. He tested my draft on an unlit stove and it was at 0. He said that’s wicked low. It was around 45 that day. I haven’t tested draft with a lit fire yet due to lack of a manometer. He’s stumped, I’m stumped. I have had an issue with ash buildi up on the tray 3-4”” of ash and only like 2” of burning coal. The coal builds up near where the pusher arm pushes it in the feed tray. I noticed a sulfur smell starting to come from the hopper when the stove is unattended. I’ve been on vacation for about 12 days now and with constant attention (raking the ash out of the feed tray and spreading the hot coal a bit) we have had no issues and no sulfur smell fron the hopper. So my question is, what’s my next step? I could try to get the tool to test my draft, and test with a lit stove. I’m also wondering if something is going on with the pusher bar motor or the pusher bar itself. Any and all advice is greatly appreciated. It’s a keystoker 90,000 btu unit. Late 90’s model. It has an upgraded 500 cfm blower motor and a digital coaltrol thermostat/controller (not nuts about this thing honestly).

I can't help with the stoker part of it but my first move would be to order a manometer and get it installed. A cheap and easy gauge is the Dwyer mark II model 25.

Other than that, crack a window open an inch in the stove room to bring the neutral pressure plane down.

Lightning wrote: ↑

Sun. Dec. 30, 2018 11:04 am

I can't help with the stoker part of it but my first move would be to order a manometer and get it installed. A cheap and easy gauge is the Dwyer mark II model 25.

Other than that, crack a window open an inch in the stove room to bring the neutral pressure plane down.

Tried the window to no avail about 2 weeks ago thinking I might just be sucking gases in.

Thanks for the make and model of manometer. Gonna order it today, just a couple questions.
Does it come with everything needed? The professional I had come had to drill a hole in the ash pan door, and stick in a needle to gauge the draft. Does that Dwyer work in the same fashion? Also does it come with mounting hardware? I tried to look on the listings I found online with none of this info..

yes, the manometers come with everything you need, you could put it in the door, or side or as close to the stove as possible in the exhaust pipe. some good threads on Manometer install on here with many options on mounting.

Definately get a draft gauge to measure exactly what your draft is. too much draft can cause it to burn back. or not enough draft to keep the fumes from building up. What are you setting on Coaltrol? you might have to bump the MIN up a couple points to get a little more heat in the chimney to maintain a better draft.

Could be grate gasket leaking towards the back if not sealed correctly, it can back burn and into the hopper. might need to be cleaned out good and resealed. I've had my keystoker over 15 years, never had a problem. sealed grate a couple times and monitor draft with draft gauge. have CO detector just about the hopper. has never gone off.

I'm not an authority by any means...but, your fire seems to be well back of the tray. Shouldn't the fire be like 2" from the end? You sure you're not pushing the coal out far enough and because of a weak draft situation, exhaust is going through the hopper? Also, get a manometer...and a steel/copper tube for the end. Check over or your fire at high-combustion and low-combustion settings. Also, check your smoke pipe at those settings as well.

You didn't mention a baro damper? Do you have one? Is it open? Closed?

What's the chimney exit look like compared to other objects in the vicinity of the house? Is it higher than the peaks of the roofs? Tall trees close? If you look on the net, you'll find some general guidelines defining a chimneys height.

You may just have a very weak draft condition and it only improves when the fire in the stove is hot. It's been pretty warm lately and perhaps you are idling your stove more often then before and the weak draft is allowing CO2 to escape?

Don

WNY wrote: ↑

Sun. Dec. 30, 2018 12:42 pm

yes, the manometers come with everything you need, you could put it in the door, or side or as close to the stove as possible in the exhaust pipe. some good threads on Manometer install on here with many options on mounting.

Definately get a draft gauge to measure exactly what your draft is. too much draft can cause it to burn back. or not enough draft to keep the fumes from building up. What are you setting on Coaltrol? you might have to bump the MIN up a couple points to get a little more heat in the chimney to maintain a better draft.

Could be grate gasket leaking towards the back if not sealed correctly, it can back burn and into the hopper. might need to be cleaned out good and resealed. I've had my keystoker over 15 years, never had a problem. sealed grate a couple times and monitor draft with draft gauge. have CO detector just about the hopper. has never gone off.

I’ve tried monkeying with the coaltrol. It doesn’t seem to make a difference either. I have the min feed rate and 10 and max is 99. The feed bar I’ve tried it maxed out, and minimum, and everywhere in between to no avail. I’ve had the stove piping hot roasting everyone in the house but the fire still burns in the back near where the coal feeds in.

I’m not sure what you mean by grate gasket. I haven’t had it that far dismantled. I did ask about possibly hopper gasket leaking but was informed by the rep I spoke to at keystoker that my model does not have a hopper gasket (upon emptying the hopper, I found out he was correct). So what is the grate gasket?

dcveem3 wrote: ↑

Sun. Dec. 30, 2018 1:46 pm

I'm not an authority by any means...but, your fire seems to be well back of the tray. Shouldn't the fire be like 2" from the end? You sure you're not pushing the coal out far enough and because of a weak draft situation, exhaust is going through the hopper? Also, get a manometer...and a steel/copper tube for the end. Check over or your fire at high-combustion and low-combustion settings. Also, check your smoke pipe at those settings as well.

You didn't mention a baro damper? Do you have one? Is it open? Closed?

What's the chimney exit look like compared to other objects in the vicinity of the house? Is it higher than the peaks of the roofs? Tall trees close? If you look on the net, you'll find some general guidelines defining a chimneys height.

You may just have a very weak draft condition and it only improves when the fire in the stove is hot. It's been pretty warm lately and perhaps you are idling your stove more often then before and the weak draft is allowing CO2 to escape?

Don

Yes, the coal fire being too at back is what my original post was about/concerning. The ash just builds up and the fire stays at the back. The pusher rod doesn’t push the ash off either and the coal just piles up back there. With constant attention it runs fine. So I’m curious what that issue is. Not sure what you mean by the coal not eating pushed out far enough due to draft? I thought the pusher bar is what pushed the ash off the tray and pushed the coal forward.
I ordered the manometer mentioned earlier, should be here in a few days. I do have a barometric dampener and I’ve had it open, closed, everything in between. Doesn’t seem to make any difference regarding the co leak. The chimney doesn’t peak over the house but I have 6.5 cleared acres (no trees) around me and the house sits on the side of a pretty big hill. We do get plenty of wind but it this seems to hold little bearing on the leak as every time the co detector has gone off I’ve made copious notes about weather conditions thinking it might be from backdraft but the conditions are always different. Cold, warm, windy, no wind I haven’t been able to see any pattern between the co leak and weather. I’ve also tried opening the air intake, closing it, half and 3/4 open, everywhere in between and that has only affected heat output but the co problem persists. Also tried slowing feed rate, increasing feed rate, still no luck.

Just found this thread:
Cleaning & Sealing Burn Grate

A nice how to for cleaning he grate. Gonna shut the stove down, grab some cement, and give it a shot. His fire seems to burn a little towards the back, but nowhere near as close the the feed area as mine...

you found it! try and and make sure it's sealed good and the holes are all cleaned out good.

The Coaltrol setting seem about right, min 10, to keep fire going on idle, not sure what max should for the keystoker, but the manual I think (if you have one) has start up settings. you should only change setting very small and and wait for it to settle out. usually once it's dialed in, you shouldn't have to mess with it at all. Also, don't use change temp by more than 1 or 2 degrees it takes a while to catch up and could over shoot, then a while to cool back down, etc... usually just leave it at a temperature and it maintains pretty well.

we will get you working properly, we've all been there, done that.

if it's not feeding properly or moving the ash off the end, make sure the grates and sides of the burn area are smooth, sometimes you have to sand them a bit to remove burrs or fused coal, also, if it doesn't feed properly, the nylon cam on the stoker could be melted (safety feature of the burn back) so it doesn't feed more if it does burn back towards or into the hopper.

Sounds like either the coaltrol or the stoker motor is not working correctly. Can you omit the coaltrol and just plug everything into a wall plug to test it. If you can get a full fire with 1 to 2 inches of ash without the coal trol you have found the issue. If not, your white puck may be worn out or your stoker motor is going... Does the pusher block move freely, it could be corroded or bound up by fines if wet coal was ever used. Might also check to make sure the holes in the grates are all clear using 1/8 punch or drill bit by hand and vacuum under the grates.

When cementing the grates, be sure to wet a finger and smooth out the cement as much as possible. bumpy, uneven cement will cause fire issues (smiley faces and uneven burn patterns). In looking at your fire, cement did not seem to be causing the issue

Check to see if the stove is level if its tipped toward the back that would cause your trouble, My sister had that problem also.

Ryan.williams wrote: ↑

Sun. Dec. 30, 2018 2:36 pm

Yes, the coal fire being too at back is what my original post was about/concerning. The ash just builds up and the fire stays at the back. The pusher rod doesn’t push the ash off either and the coal just piles up back there. With constant attention it runs fine. So I’m curious what that issue is. Not sure what you mean by the coal not eating pushed out far enough due to draft? I thought the pusher bar is what pushed the ash off the tray and pushed the coal forward.
I ordered the manometer mentioned earlier, should be here in a few days. I do have a barometric dampener and I’ve had it open, closed, everything in between. Doesn’t seem to make any difference regarding the co leak. The chimney doesn’t peak over the house but I have 6.5 cleared acres (no trees) around me and the house sits on the side of a pretty big hill. We do get plenty of wind but it this seems to hold little bearing on the leak as every time the co detector has gone off I’ve made copious notes about weather conditions thinking it might be from backdraft but the conditions are always different. Cold, warm, windy, no wind I haven’t been able to see any pattern between the co leak and weather. I’ve also tried opening the air intake, closing it, half and 3/4 open, everywhere in between and that has only affected heat output but the co problem persists. Also tried slowing feed rate, increasing feed rate, still no luck.

No, not being pushed out because of draft...but if it isn't being pushed out correctly (far enough) then a weak draft situation could allow it to leak out of the hopper. Couple that with low chimney temps and you have even a weaker draft.

I think you need to look at your pusher/stroker assembly. Clean it all out and put enough coal in the hopper to start the pushing action. No need to start a fire. Just make sure it's pushing coal down the chute. Maybe something bent and your travel isn't what it should be? I just don't think it's a grate sealing issue...it just looks like coal isn't being presented over the holes in the plates and the fire is not hot enough to promote a good draft. Just seems like a weak draft situation and everything needs to be perfect to promote proper draft.

Don't lose hope...worse case you get a power draft inducer.

Don

When you get the manometer it will come with plastic tubing that will not handle the heat from the firebox or flue pipe whichever place you use it. You will need either high temp brake line or a short length of copper tubing at the high heat area and a union to connect it to the supplied plastic tubing. I used a length of copper tubing left over from a refrigerator water line.

Thanks for all the advice. I’m going to start troubleshooting again today. Supposed to be warmer temps so I shut it down last night thinking the same. I’ll keep everyone posted.

So I got the hopper emptied out. The pusher bar is working. It pushes forward about an inch at full draw setting (turned all the way clockwise). It moves freely back and forth with no issue. There is a fiberglass gasket looking thing above it (I’m assuming this is to prevent hopper fires and act as a barrier to the burning coal) it’s not in bad shape. There is some sulfur on the sides of it telling me that the coal fire has been backed up to that point at some point in time. I’m not going to remove the pusher bar motor and assembly as it is working. I’m going to remove the combustion fan and try to clean under the grates from there and get it as best I can even though I already cleaned it last week, I don’t feel I was as thorough as I could have been. After that I’m going to pour some coal in the hopper and see how well the pusher bar and motor is working at pushing the coal in. If I see an issue I will remove the assembly and dig a bit deeper.

On the photo I attached, the green is the fiberglass gasket deal and the sides of it are where I found the sulfur. The yellow is where the pusher bar assembly oscillates forward and back. Forgive my one year old drawing skills. I have big hands and a tiny phone lol.

You'll get it....at least the weather is on your side...for now!!!

Don

Two significant tidbits I picked up reading this...

Poor Draft discovered by service tech, and fire staying close to rear of grate and hopper.

My knee-jerk suspicion is chimney leaking air in from exterior...gap or crack at clean-out door or at capped bottom or tee fitting...something is letting air into chimney besides the stove.

Gaskets on stove are not so much for keeping exhaust gases in, but rather are for keeping external air from leaking INTO the stove...same goes for a sealed chimney...keep it sealed good for good draft.