Harman mag pusher block questions
I took off plate that shows the push motor and fork. it looked very clean and parallel
I took the opp to add about 8 drops of 3in1 oil to both motor ports. there was a greasy layer on the hz shaft that the oil fills are located at the ends (I assume this is normal) you can see in attached video.
The vertical screw with shaft and lever and wing nut at the end is my question.
I manually pulled the pusher block away from stove to see how far out it comes. when looking at it from the top the silver push block only ever pulls away from stove back half way across. I will post video to show what I am talking about so that I know for sure that this is normal. To my understanding it has always been like this.
This equate to abot a 3.5 to 4dot motion if you look at it from the “dot” perspective but the first dot on my plate never really seem to be fully covered when the feed is operating, by the way there are a total of 7 dots but never have i seen the auger go past dot 4.
please take a look and let me know if the pusher block at full open appears same as mine
I took the opp to add about 8 drops of 3in1 oil to both motor ports. there was a greasy layer on the hz shaft that the oil fills are located at the ends (I assume this is normal) you can see in attached video.
The vertical screw with shaft and lever and wing nut at the end is my question.
I manually pulled the pusher block away from stove to see how far out it comes. when looking at it from the top the silver push block only ever pulls away from stove back half way across. I will post video to show what I am talking about so that I know for sure that this is normal. To my understanding it has always been like this.
This equate to abot a 3.5 to 4dot motion if you look at it from the “dot” perspective but the first dot on my plate never really seem to be fully covered when the feed is operating, by the way there are a total of 7 dots but never have i seen the auger go past dot 4.
please take a look and let me know if the pusher block at full open appears same as mine
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- Member
- Posts: 35
- Joined: Wed. Jan. 21, 2015 9:37 pm
- Location: Perry Co., Pennsylvania
- Hot Air Coal Stoker Stove: Harman Magnum Stoker
- Hand Fed Coal Stove: Harman SF-250
- Coal Size/Type: Rice or Stove Anthracite Coal
- Other Heating: Baseboard Electric
3.5-4 dots is a lot of push for a Mag Stoker. I generally run mine at 2-2.5 dots depending on outside temp. and the amount of burnt coal at the lip of the grate after a heat call cycle. I've never measured the actual distance of travel of the block but it is a pretty small stroke. While you have the side plate off check the inside dimension of the pusher fork. It should not be more than 1.75". On my stove if I run more than 3 dots it push burning coal off the grate during a heat call. Not sure if this helps.
Rick
Rick
im finding that the lower timer settings and 1 to 2 dots is too little, i just get small blue flames and orange glow close to firebricks and usually a co2 leak and the stove isnt about 200 or so.
Did you take a look at the video i want confirmation from other mag users about the pusher block and does that look similar to how far theirs can go seems like it should go more if you wanted it too but again that would be more than 4 dots and i dont know why harman has seven dots on the side plate.
Also is the long threaded screw that comes out of the pusher block, is that fixed? i know the adjust feed tube slides off and needs to be pushed up against block with the arm and wing nut screwed on the end for the pusher block to move
Did you take a look at the video i want confirmation from other mag users about the pusher block and does that look similar to how far theirs can go seems like it should go more if you wanted it too but again that would be more than 4 dots and i dont know why harman has seven dots on the side plate.
Also is the long threaded screw that comes out of the pusher block, is that fixed? i know the adjust feed tube slides off and needs to be pushed up against block with the arm and wing nut screwed on the end for the pusher block to move
That movement of the pusher block and what i call the rocker arm in your video looks like what mine does although mine is only moving 2.5 dots. I agree that 4 dots is a lot of movement and if your fork is spread wider than it should be that would cause you to need a longer stroke. Another thing that would cause the need for a longer stroke is if your coal is wet when you put it in the hopper. I noticed the rust color on the stoker housing indicating wet coal at some point.
One other thing I can think of to check is the threaded rod being snugly screwed into the back of the push block and the sleeve tight against the block.
I'm not sure what you mean by 'fixed' when referring to the threaded rod?
The timer settings that work for me are 3 min on, 15 min off, that keeps the fire going and the stove at about 300 which gives me a minimum .02 draft when in idle mode. Air intake plat is about 1/2 way open.
One other thing I can think of to check is the threaded rod being snugly screwed into the back of the push block and the sleeve tight against the block.
I'm not sure what you mean by 'fixed' when referring to the threaded rod?
The timer settings that work for me are 3 min on, 15 min off, that keeps the fire going and the stove at about 300 which gives me a minimum .02 draft when in idle mode. Air intake plat is about 1/2 way open.
Thanks for replying the threaded rod is that fixed as in screwed permanently to the block, i tried to back it out and couldnt be done, the sleeve is able to slide off and yes if it isnt pushed up against block the feed motor runs but no block movement. if yours look the same then the max number of dots a mag can push is 4. my stove is in basement and with the cold temps i am pushing like 3.2 and stove is putting out 450degrees which translates to 66 upstairs which is comfortable enough for now. Current temp is 26 degrees. if stove was in living space house would be easily 70's or more. i will take a pic of the feed motor, the "fork" looks more like two parallel hz bars that move kinda like a steam locomotive moves its wheels. purchased stove in 2006, will take a vid of that for you to compare. I take it your mag is same generation as mone. what is a good paint to use to take care of that rust this pring. i have used the spray stove paint from rustoleum on the hopper a few times. unfortunetly i do sometimes encounter wet coal but keep a 55gal barrel close to stove that i try to keep filled from my outside bin and barrels used for deliverytitleist1 wrote: ↑Mon. Dec. 10, 2018 10:25 pmThat movement of the pusher block and what i call the rocker arm in your video looks like what mine does although mine is only moving 2.5 dots. I agree that 4 dots is a lot of movement and if your fork is spread wider than it should be that would cause you to need a longer stroke. Another thing that would cause the need for a longer stroke is if your coal is wet when you put it in the hopper. I noticed the rust color on the stoker housing indicating wet coal at some point.
One other thing I can think of to check is the threaded rod being snugly screwed into the back of the push block and the sleeve tight against the block.
I'm not sure what you mean by 'fixed' when referring to the threaded rod?
The timer settings that work for me are 3 min on, 15 min off, that keeps the fire going and the stove at about 300 which gives me a minimum .02 draft when in idle mode. Air intake plat is about 1/2 way open.
Measure that fork opening...as RFK says it should be no more than 1.75".
The threaded rod is not permanently screwed into the block, it can be persuaded to come out if necessary but i've only removed one and that was because it was bent up. Is it necessary to get yours unscrewed for some reason?
Your stove temp seems low at 450 if that is during a thermostat heat call. When my 'stat calls for heat after about 20 min of running it is at 600* Do you run using a thermostat to control the stoker & combustion fan or only the control box timers?
For comparison purposes....What is your temp in the flue pipe? My flue pipe temp measured with a 2" barbeque grill temp gauge about 12" from the stoker exhaust port runs about 150 at idle and about 300 at full fire. Do you have a barometric damper and manometer? If so what is you draft and what do you have the baro set to open at? My baro is weighted to keep a max draft of .04.
The threaded rod is not permanently screwed into the block, it can be persuaded to come out if necessary but i've only removed one and that was because it was bent up. Is it necessary to get yours unscrewed for some reason?
Your stove temp seems low at 450 if that is during a thermostat heat call. When my 'stat calls for heat after about 20 min of running it is at 600* Do you run using a thermostat to control the stoker & combustion fan or only the control box timers?
For comparison purposes....What is your temp in the flue pipe? My flue pipe temp measured with a 2" barbeque grill temp gauge about 12" from the stoker exhaust port runs about 150 at idle and about 300 at full fire. Do you have a barometric damper and manometer? If so what is you draft and what do you have the baro set to open at? My baro is weighted to keep a max draft of .04.
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- New Member
- Posts: 5
- Joined: Tue. Dec. 11, 2018 3:17 pm
- Stoker Coal Boiler: Harman Magnum Stoker
- Coal Size/Type: rice
- Other Heating: oil
I just purchased a 06 Harman Magnum Stoker for $500. I'm setting it up and the push block is coroded fast. Any suggestions or helpful hints to get it moving would be greatly appreciated. I'm new to stokers and the site. Thanks Dan
- McGiever
- Member
- Posts: 10130
- Joined: Sun. May. 02, 2010 11:26 pm
- Location: Junction of PA-OH-WV
- Stoker Coal Boiler: AXEMAN-ANDERSON 130 "1959"
- Hand Fed Coal Boiler: BUCKET A DAY water heater
- Hand Fed Coal Stove: Warm Morning 414A
- Coal Size/Type: PEA,NUT,STOVE /ANTHRACITE
- Other Heating: Ground Source Heat Pump and some Solar
Welcome Partner!
You came to the right place...
Remove the rear nut and over tube from the rod, remove the grates from inside the front of the stove, then tap lightly on the end of the rod w/ a hammer and a block of wood to protect the rod threads.
The aluminum block will enter into the lower grate area inside the front of the stove and then you will need to remove/unscrew the rod entirely from the aluminum push-bar at the rear side .
This will enable pushing/pulling maybe even tapping the last little bit of the aluminum push-bar the rest of the way inside until free...then you simply lift it out by hand from the removed grate area inside the front...
Wet coal and coal fines and/or leaving coal in hopper from one season till the next will cause a black cement like buildup to bind the block...a good scrapping is in order to get it clean again.
Bound push- block can force or spread open the "fork", or in a sever case might ruin the motor or gears...fork wants to be 1.75 inch spread.
HTH
- coalkirk
- Member
- Posts: 5185
- Joined: Wed. May. 17, 2006 8:12 pm
- Location: Forest Hill MD
- Stoker Coal Boiler: 1981 EFM DF520 retired
- Hand Fed Coal Stove: Jotul 507 on standby
- Coal Size/Type: Lehigh anthracite/rice coal
My previous boiler used that same stoker. Annual maintenance goes a long way to avoiding problems with this pusher block. I can see from the video that it looks a little crusty from using wet coal. Slightly damp coal is ok but wet coal is not. I would remove the stoker and disassemble the whole thing after the heating season, clean and repaint the housing. Obviously do not paint the pusher block. Take the pillow blocks out and clean everything. When I sold that boiler after about 18 years of use the stoker looked like new. Also don't leave coal in the hopper in the off season. Clean it out and paint the inside with a good quality paint. I used rustoleum rusty metal primer. Those hoppers are quite pricey and you don't want to have to replace it.
yes I got complancent and will do a thorough clean this spring. As for paint do you only use the rustoleum primer? or is there another paint you put on top? I asssume the HD\Lowes have the rustoleum. What are the pillow blocks?coalkirk wrote: ↑Thu. Dec. 13, 2018 7:47 amMy previous boiler used that same stoker. Annual maintenance goes a long way to avoiding problems with this pusher block. I can see from the video that it looks a little crusty from using wet coal. Slightly damp coal is ok but wet coal is not. I would remove the stoker and disassemble the whole thing after the heating season, clean and repaint the housing. Obviously do not paint the pusher block. Take the pillow blocks out and clean everything. When I sold that boiler after about 18 years of use the stoker looked like new. Also don't leave coal in the hopper in the off season. Clean it out and paint the inside with a good quality paint. I used rustoleum rusty metal primer. Those hoppers are quite pricey and you don't want to have to replace it.