Harmon Magnum Stoker - Draft Issue ?

Hello my Father-In-Law is having some issues with his Harmon Magnum Stoker Stove. Below is the letter to Harmon, I will also include some other points.

Question: Hello, my Father-In-Law has a Magnum Stoker coal stove, it is about ten years old and last year it developed a problem where he was getting carbon monoxide reading ( around 30) on his detectors. We called the installer (SOS Stoves & Fireplaces) to diagnose the issue, they recommended a new combustion blower. Well needles to say this did not resolve the issue and they (SOS Stove) could not resolve the the issue after a handful of visits. I read further into this myself in regards to draft in the chimney and making sure the firebox is running in a negative environment ( I have a bacharach draft gauge along with a dwyer manometer). Following all instructions I can achieve -.04 on the chimney draft and -.02 in the firebox even with the shutter on the combustion blower mostly closed. I also notice his coal has a incomplete burn compared to my coal stove (I have a keystoker). I made a phone call to another Harmon dealer and they said they only service what they install. Does Harmon have a area representative in northwestern New Jersey? Maybe another dealer can resolve this issue? Thanks for any help you can provide.

Here was their response:
There are 2 other dealers who may be able to help.
1) Hinton and Sons in Wind Gap, PA 610-863-8182
2) Stoves-N-Stuff in Stroudsburg, PA 570-424-2421

I called one dealer and they informed me that they can only work on the stoves that they installed. Harmon says that that is not true. Can you imagine only being allowed to go back to the dealer where toy purchased a car from ?
Another dealer wants a credit card number before coming out and looking at it. Again, very strange.

So here is what we know about the stove:
It is about ten years old and operated fine for around eight years.
Installed in a ranch home in the living room.
New chimney we also installed at time of stove purchase.

Please chime in with any ideas you all might have. Has anyone ever had this issue? Personally I think I will disassemble the stove and clean everything and install new gaskets. That with a chimney sweep and camera inspection.

When you say new chimney...do you mean the existing chimney was lined ?
I woul contact who ever performed the " work "on the chimney originally.
If it indeed was lined...it may be failing due to age..and corrosion.
CO levels do indicate an incomplete combustion..
But a failing chimney could be causing poor draft also...
Also...CO detectors should be CHANGED every 5-7 years...
If the stove is heating as normal...i would certainly invest in a new detector for sure

Also...the chimney should be cleaned annually- at minimum

In addition to Rigar's....here are a couple questions.....

Are the CO detectors 10 years old also? Does he also get the rotten egg sulfur smell?
Does the underside of the hopper lid get moisture on it?
You say mostly closed on the combustion fan baffle, mine is open about the width of my index finger, how does that compare to yours?

Have the grate holes been reamed out? Is the burn pattern even across the grates? how high is the flame when on full burn for about 5 minutes (not pilot mode) and how far back doe the fire line get? How much ash on the front of the grates?

have all horizontal sections of flue pipe been vac'ed recently and is that pipe in good shape?

Is he burning coal from the same source as when successfully burning and is the size / fines about the same?
Is the coal dry, damp or wet?
Is he getting only coal dust in the fines tray and not any rice coal nuggets?

ok, that was way more than a couple questions! But it helps when diagnosing over the net to have as much info as possible....

WOW .. thanks or all the replies.

Chimney is a metal construction that travels vertically from the stove to the roof of the house. It was new when the stove was installed and has been swept annually. We have contacted the original installer. They have no idea how to remedy the problem.

CO detectors are new within the last two years. I have also brought my TSI Indoor Air Quality meter home from work and get the same reading when I am data logging.

No moisture and the coal is dry.

The burn is fine and there is ash on the end of the burn plate. No modifications of the holes.

Thanks again..

bug512 wrote:
No moisture and the coal is dry.

The burn is fine and there is ash on the end of the burn plate. No modifications of the holes.

Thanks again..

my bad....i didn't mean if the holes were modified, just cleaned out. the manual recommends a drill bit to clean them and keep the air flowing freely through them. do you have about 1" of ash on the end of the grate or more?

If the burn is fine and you aren't getting moisture in the hopper indicating exhaust going through there, I'd check the door gaskets, then the gasket that seals the stoker assembly to the stove body. for the door gaskets, pinch a $ bill in it with it latched and see how easy or hard it is to pull it out while latched. It should not be easy.

if those are all sealed up, there isn't any other designed openings in the stove for the CO to get out.

Do you have access to a manual, if Harman has them on the website or I can email one to you. There is a decent exploded view of the stove.

I will have to confirm if the door gaskets have been changed with him.

I do have the original owners manual.

There is ash at the end of the grate, the stove hardly ever runs "full out" since it's located in the living room (in a ranch house).

I think a tear down and re-gasket everything is in order. Just a shame that the support through Harmon and their dealers is so poor (in my opinion).
Have any of you re-gasketed your stove?

If the chimney deems o.k. after a thurough visual inspectio. ( no obstructions...clean...no corrosin...etc)
...def inspect all gaskets
Is there a fire place in the house?.... could the stove experience a bad backdraft ?

... just to throw this out there... is there any possibility that the CO levels are being produced by another appliance in the house(water heater..furnace etc ?)

...have you shut down the stove completly and then monitored the air quality?

bug512 wrote: Just a shame that the support through Harmon and their dealers is so poor (in my opinion).
Have any of you re-gasketed your stove?

AMEN regarding the poor support.....for the inverse of that just look at how accessible the LL guys are and the support they give, to the level of putting their cell # in the manual.

I replaced the door gaskets on my hand fed harman about every 2 years, although with the stoker doors being opened a lot less i may go 3 years before replacing them. This is my second year for the stoker in the house and third for the one in the workshop and both stoves gaskets are OK. I had replaced them when I got them used. I'd have to look at my notes to be sure, but I believe it is 1/2" rope gasket on the doors.

Thanks everyone you have been great.

No there is no fireplace in the house, electric water heater and oil fired warm air furnace that is not on since the coal stove is running.

I have a Ridgid snake camera that I will do the chimney inspection with.

Update: ordered all new gaskets. I will plan on doing a tear down and re-gasket the stove over Presidents Day weekend. I will be sending the camera down the chimney before and after the brush.

Thanks again for all of your suggestions. Really do appreciate them.

Hopefully that does the trick...
Keep us posted

Update: Last Sunday (2/24) I disassembled every piece on the stove. The gasket where the feeder and the stove meet was very compromised. All other gaskets were replaced with Harmon gaskets. He had once replaced the door gaskets with another brand the the rope thickness was considerably smaller compared to the Harmon gaskets. I emailed with Harmon about the feeder gasket placement and here is the conversation.

My question:
Question: I am replacing the gasket on the main feeder body. I see the gasket I removed was between the stove and feeder assembly alone with some stove cement. Do I also want to place a gasket on the flange where the feeder assembly makes contact? Do you have a better drawing of this?

Their response:
The gasket goes around the opening in the stove body only and is not needed on the flange of the feeder body. The gasket has self adhesive to adhere to the stove body opening. The only drawing is on page 7 of the owner’s manual.

My response:
Thanks for the reply. I installed the gasket in the manner the old one was removed. There is a lot of space (not a snug fit) between the feeder body and the gasket / stove. I see that there was stove cement used very sparingly on the sides. Is it "normal" for that not to fit in a better manner? Also I did review the owners manual and I see another illustration the make it look like the gasket is rolled over the lip of the flange.

And their final:
The gasket must be rolled over the edge of the opening in order to achieve a proper seal. The feeder mounting bolts will draw the feeder flange tight against the gasket.

So as you can see first they tell me it is not needed then the gasket must be rolled over... What? Look at page 7, to me it looks like the gasket goes only inside the opening.

I had enough gasket to use on the stove body and on the flanged piece where the stove meets the feeder assembly. They also made no comment on where the stove cement is to be placed so I applied where it was removed.

It's been running 24+ hours and I called my Father-In-Law this afternoon on the way home from work and he said everything is running well.

Thanks for everyones nut and comments.

lol...my keystoker manual explained how to bolt the heat exchanger (heavier than hell) to the combustion chamber......3 steps later it explained how to put the gasket between the two (i knew better and installed it )
...i called them on it tho...and suggested they put step 5 before step 3...for the guy that doesnt know any better....lol

any ways...glad to hear ur problem is solved!

I called one dealer and they informed me that they can only work on the stoves that they installed

Sounds like Hinton & Son. Wouldn't buy anything from him. Several years ago he had 2 warehouses full of pellets, when pellets were hard to get. He only sold them to people who bought stoves from him. The kicker of it all was..... He only brought 20 pallets to shop on a Saturday, Sunday and jack up the price by $50 a ton