Harman Magnum Stoker questions

 
MBY1911
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Post by MBY1911 » Thu. Mar. 30, 2023 5:21 pm

I've been having a few issues with my Harman Magnum Stoker.
Recently my CO alarms started going off.
The weather was pretty wet at the time, but it also seemed like my stove stopped pushing coal and the fire was burning towards the back of the grates.
The pusher was working going back and forth but I noticed that it doesn't go to the 1st dot that shows how much its pushing. It only goes to the 2nd dot.

I took all the coal out of the hopper and vacuumed out the coal. tested it and it seemed ok otherwise.
Put coal back in and it seemed to work for a bit but then seemed to stop pushing again and CO alarms going off.

This time I took all the coal out, removed the hopper, removed the pusher motor cover, vacuumed out and used air compressor to blow out anything inside.

After that it I haven't seen any issues with CO alarms or it not pushing - so far (it's been a few days now).

While I had everything off, I noticed that the sleeve over the pusher rod doesn't go up tight against the block. I could push it tight but when the motor pushes it back, it's loose again.
Looking at some other forum posts there is talk about a "fork" but I am not sure what that is?
I looked at the parts list for the stove (http://static.legacystoves.com/150401-dealer/Part ... Stoker.pdf) and I'm guessing it's the U shaped portion of part 9.17?

Would that prevent the sleeve from staying up tight against the block though? I'm having trouble understanding how that would be the case?
I should add that I pushed the sleeve all the way tight, screwed the adjuster wing all the way tight, and screwed the wingnut all the way tight and it still did it.
If that's not it, what else could be the issue?

Right now, the fire seems a bit further back on the grate than where I think it should be. Can someone post a photo of where it should be so I can compare?
I'm guessing that's part of the feeder issue?

I also bought a Dwyer 25 Mark II manometer but didn't realize it didn't come with a probe. Can anyone tell me what size probe I need for this and/or recommend one?

Thanks!


 
MBY1911
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Post by MBY1911 » Sat. Apr. 01, 2023 7:41 pm

Also add that I cannot get the set screw removed for testing draft with a manometer. I'm guessing its probably rusted in there. Any recommendations for getting that free?

 
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captcaper
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Post by captcaper » Wed. Apr. 05, 2023 8:07 am

The fork can spread open. Check and see if it's about 1 3/4 in . That happens when there is resistance against the feeder block. I used to pick up chunks in the Rice in that area and jam up the feeder block and that would open the fork. It actually cracked it and I had it welded up with support. I now screen the Rice with 3/4 x 3/4 heavy screen into large totes first. No problems now. It picks up many chunks.

 
MBY1911
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Post by MBY1911 » Thu. Apr. 06, 2023 6:21 pm

I got the screw removed using WD40.

 
MBY1911
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Post by MBY1911 » Thu. Apr. 06, 2023 6:22 pm

captcaper wrote:
Wed. Apr. 05, 2023 8:07 am
The fork can spread open. Check and see if it's about 1 3/4 in . That happens when there is resistance against the feeder block. I used to pick up chunks in the Rice in that area and jam up the feeder block and that would open the fork. It actually cracked it and I had it welded up with support. I now screen the Rice with 3/4 x 3/4 heavy screen into large totes first. No problems now. It picks up many chunks.
Is it the U shaped portion of part 9.17?
http://static.legacystoves.com/150401-dealer/Part ... Stoker.pdf

 
MBY1911
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Post by MBY1911 » Thu. Apr. 06, 2023 9:14 pm

I took out that u shaped piece and it was 1/8 of an inch larger than 1 3/4 inch on the interior parts of the U.
You have to take out the motor to get it out (at least I did). That was not fun, especially with limited space.

I got it down to 1 3/4" but that did not fix the pusher issue. It still doesn't go to the first dot.

I cleaned stuff out inside there when I had everything out as well.

 
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captcaper
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Post by captcaper » Wed. Apr. 12, 2023 6:18 pm

MBY1911 wrote:
Thu. Apr. 06, 2023 9:14 pm
I took out that u shaped piece and it was 1/8 of an inch larger than 1 3/4 inch on the interior parts of the U.
You have to take out the motor to get it out (at least I did). That was not fun, especially with limited space.

I got it down to 1 3/4" but that did not fix the pusher issue. It still doesn't go to the first dot.

I cleaned stuff out inside there when I had everything out as well.
The pusher block won't go to far if it's warm out and there isn't a demand for lot's of heat. It only moves a hair then after a while more fractions of an inch. Also I have to oil the pusher block in front and on the sides as it get's gunked up and makes nosies.


 
MBY1911
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Post by MBY1911 » Fri. Apr. 14, 2023 8:49 pm

captcaper wrote:
Wed. Apr. 12, 2023 6:18 pm
The pusher block won't go to far if it's warm out and there isn't a demand for lot's of heat. It only moves a hair then after a while more fractions of an inch. Also I have to oil the pusher block in front and on the sides as it get's gunked up and makes nosies.
I thought the pusher bar was controlled by how far in you have the screw on the pusher rod adjustment threaded in?
I had that threaded all the way in.

The manual says:
To start a fire, you first pour rice coal into the hopper. With the thermostat turned up and the stoker
running, the coal will begin to feed onto the grate inside the stove. This process can be accelerated
by adjusting the feed rate to the maximum position

Adjust feed rate by turning adjuster clockwise to increase
and counterclockwise to decrease. Each complete turn will
move the fire about 1".
The feed indicator on the side of the feeder shows how far
the pusher moves each stroke. There are dots above the
indicator spaced 1/8 " apart. A movement of one dot would
give a low burn, two dots medium and three dots high. Lock
the adjuster with the wing nut after adjusting



so there are like 7 holes * * * * * * *
Then there is a little arrow that is attached to the block that points to the holes ^
| equals back of stove.

1 2 3 4 5 6 7
* * * * * * *|
------------ ^

The above is how far forward the pusher goes (hole 6).

So I guess now I'm confused which hole is the starting point? Is it hole 1 or hole 7?
I am thinking hole 7 is the starting point.

It never gets to hole 7 with everything turned all the way in.
It never got past hole 3 or 4 when the pusher block is moving away from the stove.

I can manually push the pusher block to hole 7 but once the stove pushes it back and forward again, it only goes back to hole 6, not hole 7

 
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Post by HarmanStoker » Mon. Apr. 17, 2023 6:04 am

Hi, here is a picture of a fire in my Harman Stoker while the stove is in the on portion of the cycle. It's not a perfect fire, it should really be burning about 1" from the edge of the grates.

I'm not 100% sure, but I think the dot pointer starts in the middle and extends further back and forward with the feed rate adjustments.

I've also had some trouble with CO alarms recently, I think the hot, damp weather challenges the draft. I cleaned my stove and bottom of the chimney really well to make sure they're wasn't any ash in the way of air flow and that seemed to help in my case.

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HarmanStoker
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Post by HarmanStoker » Mon. Apr. 17, 2023 9:49 am

captcaper wrote:
Wed. Apr. 05, 2023 8:07 am
The fork can spread open. Check and see if it's about 1 3/4 in . That happens when there is resistance against the feeder block. I used to pick up chunks in the Rice in that area and jam up the feeder block and that would open the fork. It actually cracked it and I had it welded up with support. I now screen the Rice with 3/4 x 3/4 heavy screen into large totes first. No problems now. It picks up many chunks.
Did you make the screen or is there somewhere I could purchase one?

 
MBY1911
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Post by MBY1911 » Tue. Apr. 18, 2023 5:12 pm

HarmanStoker wrote:
Mon. Apr. 17, 2023 6:04 am
Hi, here is a picture of a fire in my Harman Stoker while the stove is in the on portion of the cycle. It's not a perfect fire, it should really be burning about 1" from the edge of the grates.

I'm not 100% sure, but I think the dot pointer starts in the middle and extends further back and forward with the feed rate adjustments.

I've also had some trouble with CO alarms recently, I think the hot, damp weather challenges the draft. I cleaned my stove and bottom of the chimney really well to make sure they're wasn't any ash in the way of air flow and that seemed to help in my case.

Starting in the middle doesn't seem to make sense in my opinion but I could be wrong.

That looks about where mine was burning a lot of the time recently.
It usually burns more towards the front .

I think the warmer damp weather is an issue with CO alarms also.

 
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Post by MBY1911 » Tue. Nov. 28, 2023 4:34 pm

I am trying to use the manometer for the first time. I have it set so red liquid is at 0 and it's leveled. The 1 tube is connected to the high plug and that same tube has the probe on it. I have the stove running now and inserted the probe into the front of the stove. The manometer is not changing at all. Sitting at 0. If I stop holding the manometer all the way in it moves slightly and the meter reading fluctuates from about 0 to -.01.

How long does the stove need to be on to get a good reading?
How far into the stove does the probe need to be? If it's all the way in it touches the feed tray.

The stove manual says it should be between .04 and .06.
A video I found about installing the manometer says it should be around -.02 but that is a different stove so not sure that applies here.

The stove manual also says to try closing the feed blower door and check the meter. If I close it all the way it drops the meter to as low as -.03 but tends to stick around -.01 or -.02 at times.

So I guess that's not enough draft right?
How can I add more draftm
Or am I doing this all wrong?

 
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nepacoal
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Post by nepacoal » Tue. Nov. 28, 2023 5:14 pm

After a long idle, my Keystoker's draft will be zero for a few minutes and then start climbing to it's -.02 set point. It'll take almost 20 or 25 minutes to get all the way to -.02.

It will respond much faster in cold weather (say lower than 25°) because it's running more often and keeping the chimney warmer.

 
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Post by MBY1911 » Tue. Nov. 28, 2023 6:26 pm

I was re-reading some other threads on the manometer so I put the tube on the low port and it goes up to about .01 or .02 and it may stay there, or may drop back to .01.
At least 2 times I made it go up to like .05 by opening and closing the combustion blower but it didn't stay there and went back to .01 and it's not repeatable.
It seems that full open on the combustion blower makes it go closer to 0. whereas fully closed or almost fully closed makes it go to .01 or .02.

I also drilled a hole into the pipe coming out of the stove about 12 inches above stove and put the probe in there but that didn't seem to make any difference. Still read at about 0 or .01.

I'm very confused on how I should be using the manometer. Do I use the high or low port? Do I need to use both tubes? Where should the probe go? What numbers should I be looking to get on the meter (I assume .04 to .06 per the stove manual)?
I can't get the probe to stay in all the way. Does it need to be in all the way? Does it need to be level?

 
waytomany?s
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Post by waytomany?s » Tue. Nov. 28, 2023 6:29 pm

Aim for what the manual says and go from there. You are checking during a heat call after it has ramped up and ran steady for IDK 15-20 minutes?


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