KA -6 ?

Stoker Coal Boilers automatically feed the coal and have controls and pumps just like any conventions boiler. They are intended to be used as a primary heat and often have domestic hot water coils as an added bonus. They can be set up independently or in dual sytem with your existing oil/gas boiler. They can accommodate both hot water base board or steam plumbing.
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Post Tue. Jan. 29, 2013 7:08 pm

Wow all alittle overwhelming , been using a 90,000 BTU wood boiler and ready for coal . Really cold nights in Maine really drag it down when garage radiant comes on , then hot water then bedrooms . Been looking at ka-6 from keystoker and wondering if it's too big . I think my plumber rated the house for 69,00 BTU ,might not have figured in basement. House is 1500' with registers , garage (radiant) 900' basement (radiant) 800' . New modular home heats well above 0 but man you can't lug enough wood when it's below 0 . My oil is 100,00 will keep up but sure runs alot . My concern is too much overboil if ka-6 is too big . I will probably only use for winter season

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Hot Air Coal Stoker Furnace: Keystoker A 150
Coal Size/Type: anthracite rice
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Stove/Furnace Model: A 150 warm air furnace
Location: central new york (syracuse area)

Post Tue. Jan. 29, 2013 8:17 pm

So you have atotal of 1700 sq ft radient between the garage and basement?
And heating 1500 sq ft living space with how many feet of basebaord?
Where is boiler now - basement or garage ?
Is garage attached or no

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Stoker Coal Boiler: Keystoker KA-6
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Stove/Furnace Model: KA-6
Location: Phillipsburg NJ

Post Tue. Jan. 29, 2013 8:43 pm

I can't follow all of your numbers, but I have a KA -6 heating a 2000 sq ft two story house. If you have it set up correct I don't think you can
" over boil". You must have the proper draft with a good chimney, coal needs that. I'm burning buckwheat oiled coal. My fifth year. Your wife will like the hot water in the shower! Go to the site inspectapedia and learn how a triple aqua stat works. This will be something worth learning. Some furnace servicemen don't know how they work.

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Post Tue. Jan. 29, 2013 9:21 pm

Welcome Arte, nice too see another mainah ready to be warm and saving a few bucks. This is my second successful yr. thanks to the folks here!
never yell through a screen...you'll strain your voice.

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Rick 386
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Stoker Coal Boiler: AA 260 heating both sides of twin farmhouse
Hot Air Coal Stoker Stove: LL Hyfire II w/ coaltrol in garage
Coal Size/Type: Pea in AA 260, Rice in LL Hyfire II
Other Heating: Gas fired infared at work
Location: Royersford, Pa

Post Tue. Jan. 29, 2013 9:47 pm


First off, welcome to the forum.

Secondly, where in Maine are you? Sterling40man (Bob) is way up north in no man's land and heats his place with a KA 6 in the garage. Send him a PM and I'm sure he can answer any question you have.

A fairly new modular up there should have come with plenty of insulation. So heating it should not be much of a problem.

Master of "Trial and Error."

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Stoker Coal Boiler: Keystoker Ka 6
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Post Wed. Jan. 30, 2013 5:45 am

Personally I wouldn't be to concern if it's bigger then needed. 1700 sq ft with Maine temps I would get the Ka-6 and not worry if it'll keep up. Also if you add onto garage you'll have a boiler that will handle the extra sq ft
If you have time to make a post looking for free advice, then show some appreciation and say thank you.

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oliver power
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Stoker Coal Boiler: KEYSTOKER Kaa-2
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Baseburners & Antiques: MANY (Mostly when burning wood)
Location: Near Dansville, NY

Post Wed. Jan. 30, 2013 7:02 am

I heat my 1700 square foot with a Kaa-2 in basement. It does a very good job. I'm very happy with it. However, once I add my hot water to the load, I believe it will be maxed out, or close to it. Should I want to add an out building, garage, etc., I don't think the Kaa-2 would handle it. If I had to do it over again, I'd buy the Ka-6. Put it in a central location, and heat my house, shop, and future garage. I also wouldn't be carrying coal "Down" into basement, and ash "UP" out of basement. One more thing to think about; I tend my Kaa-2 every 24 hours. Should you go out of town for more than 24 hours, the Ka-6 has a bigger hopper, as well as a bigger ash bucket. Actually, the Ka-6 has an ash tub, not bucket. Oliver

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Rob R.
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Location: Chazy, NY

Post Wed. Jan. 30, 2013 8:27 am

Hi Art - Here is some good info about boiler sizing.

Keystoker KA-6

If it were me, I would ask Keystoker if they could put a KB-8 stoker an a K6 boiler...they used to do this for steam boilers to give them some extra punch without the larger footprint. The Keystoker design is very rugged and simple, but if you get some coal that is prone to clinker it can cause problems when the stoker is running hard.

Do not base your boiler size on what someone else is heating with it. No two houses heat the same, and you are not exactly in the tropics... :) You want to size the boiler to allow for less than ideal conditions, such as mediocre coal, or a boiler that is overdue for a mid-season cleaning. Don't worry about the boiler overheating, these stoker boilers will idle for days on end just like a big diesel engine...but without the smoke. ;)

How warm do you keep the garage?

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Stoker Coal Boiler: Keystoker K6
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Location: Northern Maine

Post Wed. Jan. 30, 2013 9:14 am

Rick 386 wrote:Sterling40man (Bob) is way up north in no man's land and heats his place with a KA 6 in the garage.
That's me! :lol: I love my K6! I'm heating my 2,400sf house at 72* and my 1,200sf garage at 42* with no problems at all. Shoot me a PM if you have any questions.
"I think the next best thing to solving a problem is finding some humor in it."


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Post Wed. Jan. 30, 2013 4:32 pm

Have you seen the KA-6? Logistically speaking, she is a BIG GIRL! So big, it makes the KA-2 look tiny.

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Post Wed. Jan. 30, 2013 7:37 pm

Had a chance to see one last weekend , about twice the size of my wood boiler . I've got lots of room after storage for 8 cords of wood easily

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Stoker Coal Boiler: Axeman-Anderson AA-130, Keystoker K-6
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Post Thu. Jan. 31, 2013 10:00 am

Same concern I had when I first started looking. I have a KA-6. I can idle for days at 140 to 150 deg boiler temp. No problem with the lighter load. Plenty of extra capacity for DHW.

KAA-2 will be too small for you.

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