520 Flue Size...

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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Posts: 22
Joined: Sun. Feb. 17, 2008 6:56 pm
Stove/Furnace Make: Harman Mk III
Location: Killingly, CT

Post Thu. May. 22, 2008 9:02 am

I finally saw a 520 in action yesterday, and I noticed it has an 8" flue outlet...can that be reduced to 7" or would I have to blast out my chimney opening to use one?

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Verified Business Rep.
Posts: 2063
Joined: Mon. Nov. 19, 2007 9:33 pm
Hand Fed Coal Boiler: 1981 efm wcb-24 in use 365 days a year
Coal Size/Type: Anthracite/Chestnut
Other Heating: Hearthstone wood stove
Location: Lehigh Valley, PA

Post Thu. May. 22, 2008 11:17 am

I can't recommend anything but what efm calls for....8" chimney.

I know for a fact that many use smaller chimneys because they have good draft. It is usually permissible to have a chimney 1 inch less depending upon the firing rate, but for me, it's the official "line".

Posts: 22
Joined: Sun. Feb. 17, 2008 6:56 pm
Stove/Furnace Make: Harman Mk III
Location: Killingly, CT

Post Thu. May. 22, 2008 12:29 pm

I believe my chimney tile is 8x8, but the existing thimble is for a 7" smoke pipe for my oil boiler...it's the smoke pipe I would have to reduce...I imagine I could chop it out but I wouldn't want to if it wasn't necessary...

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coal berner
Posts: 3591
Joined: Tue. Jan. 09, 2007 12:44 am
Stoker Coal Boiler: 1986 Electric Furnace Man 520 DF
Stove/Furnace Make: Electric Furnace Man
Stove/Furnace Model: DF520
Location: Pottsville PA. Schuylkill County PA. The Hart Of Anthracite Coal Country.

Post Thu. May. 22, 2008 3:40 pm

1 " will not make a differents get you self a 7 to a 8 reducer for the thimble you will be fine use 8" to the stoker

Heating house & water with a 1986 electric furnace man DF520 using buckwheat Anthracite coal

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Posts: 1285
Joined: Fri. Feb. 16, 2007 10:31 am
Stove/Furnace Make: EFM
Stove/Furnace Model: 520
Location: western ny

Post Fri. May. 23, 2008 9:18 am

If you plan on running the boiler full steam : 10 teeth, full feed then I'd go 8", In my opinion even a 6" pipe would be fine if only running the boiler at the average 4 teeth.
Burning coal is definitely worth the extra work involved.
"Good enough" is not good enough.

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Posts: 2597
Joined: Tue. Jan. 08, 2008 9:51 pm
Stoker Coal Boiler: EFM 520, 700, Van Wert 800 GJ 61,53
Baseburners & Antiques: Magic Stewart 16, times 2!
Coal Size/Type: Lots of buck
Other Heating: Slant Fin electric boiler backup
Location: Malta N.Y.

Post Fri. May. 23, 2008 10:03 pm

I run 6" and can't wait to get a bigger chimney. Seems I get a wiff everytime the stoker starts. Sort of like it :) Scott
I think a man does what he can, untill his destiny is revealed. Right now that is trying to sell my EFM plate boilers in 520 and 700 sizes.

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