How to Clean a Harman Mark III?

Modern and vintage hand fired coal stove are similar to a wood stove and in some cases can burn either. They need to be regulated and fed by hand usually every 12 to 24 hours depending on your usage. They require no power to operate making them ideal for rural settings with long power outages.
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Posts: 52
Joined: Thu. Nov. 22, 2007 5:11 pm
Stove/Furnace Make: Harmon
Stove/Furnace Model: Mark III
Location: Waynesboro, Pa

Post Sat. Mar. 08, 2008 10:58 pm

What do I have to do to clean my Harman Mark III for the closing of the heating season? Do I have to remove the pipe from the stove as well. I was thinking that if I did that the house would get fly ash all over the place. Any help would be appreciated.



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Posts: 7385
Joined: Sun. Nov. 20, 2005 8:02 pm
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland
Location: Michigan

Post Sun. Mar. 09, 2008 4:16 am

The best method is to remove the flue pipe completely, and wipe/wash the inside of the pipe and the stove with a solution of baking soda and water. Vacuum out the fly ash first of course.

The baking soda solution [one box in a 2-gallon bucket of water] helps to neutralize the acids in the ash. Normal summertime humidity will activate the acid in the ash, and you will have your flue pipes rust away just sitting there..

So: a good vacuum, and a wash/wipe with the soda solution, and if you want some form of rust preventative. or keep a light bulb burning in the stove to keep it slightly warm, to drive off the humidity.

Greg L
Burning Pea/Buckwheat through an antique stoker [semi retired SSboiler],
Running an Axeman-Anderson 260M boiler burning Pea, About 150-250#per day
Farming, Fixing, Fabricating and Flying: 'spare time' what's that?

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Posts: 4404
Joined: Wed. Nov. 14, 2007 4:06 pm
Hot Air Coal Stoker Stove: Harman Mag Stoker (old style) one in basement, one in workshop
Hand Fed Coal Stove: Harman Mark III on standby for long power outages
Coal Size/Type: Rice/Anthracite; Nut/Anthracite
Location: Cecil County, MD

Post Mon. Mar. 17, 2008 10:50 am

When you vacuum out the stove make sure you get on top of the baffle, ash likes to lay up there. Another place it accumulates is inside the flue port on both sides between the interior jacket and the outside wall of the stove (if it is a rear exhaust and not a top exhaust). I can just barely get the hose from my small shop vac to fit in those cavities in the back, my larger shop vac won't fit.
I drive a VW TDI, heat my home & workshop with two coal stokers and have two vintage JD diesel tractors....
The EPA just loves me!!

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