Mark II Durability Without Blower ?

Mark II Durability without blower ?

PostBy: Uglysquirrel On: Sat May 17, 2008 1:57 pm

Hello all, I searched for the following question before posting it here though this question may not have been asked before. If the blower is not used, can stove damage occur if it is operated at a high normal operating temperature ? I read an valued forum opinion recently suggesting that since the rear of the stove has a double wall with blower air washing in between, that not using the blower may damage/warp certain parts of the stove. We all understand that the baffle (which to my understanding is directly above the firebox) can distort with overfiring though that makes sense. As far as my feeble mind can read, manual does not mention a requirement to run the blower. My opinion is no damage in high normal operation w/o blower on should occur since, for example, the TLC 2000 has (to my understanding) a similar internal plenum design and that comes with an OPTIONAL blower. Reason for asking: may not need all the heat at times from this firebreather though a lot of you have made excellent comments regarding being able to idle this beast down big time. I'm sure there is a lot of Mark I,II,III experience out there that would address this question. Comments appreciated from the coal masters.

Too warm out today, November is ~ 7 months away
Stove/Furnace Model: Pocono

Visit Hitzer Stoves

Re: Mark II Durability without blower ?

PostBy: CapeCoaler On: Sat May 17, 2008 2:25 pm

It is never too warm to run a coal stove!
The Mark II is idling, no fan, windowstats functioning and it is 73 inside. Today was typical coastal New England; rain, wind, cold morning followed by sun, calm, warm afternoon.
Normally you would kick the fan on to get more heat rather than upping the stove temperature because if you do you are operating inefficiently, most of that extra heat is going up the chimney. That said I did accidently leave the ash door open for 6 hours with a fresh load of coal! The stove temperature was at the upper end of what I normally run it in the winter. No fan was running and there was no damage to any part in the stove. The upper air channels are “U” shaper ¼” steel not a double wall. I believe the back is similar in design. The stove is not a true double wall or else the clearance setbacks would be closer. It takes a lot to hurt the plate steel so unless you get the stove “glowing” you should be fine.
Stoker Coal Boiler: want AA130
Hand Fed Coal Stove: DS Machine BS#4, Harman MKII, Hitzer 503,...
Coal Size/Type: Pea/Nut/Stove

Re: Mark II Durability without blower ?

PostBy: Uglysquirrel On: Sat May 17, 2008 3:09 pm

Thats amazing, still doing coal, max idle mode, continue to hear how these can be idled nicely which is what I likely will need. Thanks for the reply on high heat w/o blower, just want to do things right, I'm one of those enjuneers who analyses everything (one of those....)
Stove/Furnace Model: Pocono

Re: Mark II Durability without blower ?

PostBy: LsFarm On: Sat May 17, 2008 3:24 pm

My answer to your question is pretty much the same.. Just look at the times when you would want less heat, afternoon with the sun out.. you wouldn't just turn off the fan,, you would also turn in the air control as well.. I can't see a scenario where you wanted enough heat to possibly damage the stove, and not have the blower on. They kind of work together..

Once you get the stove installed and use it for a few weeks or at least through several weather changes, you will get 'a feel' for the best settings, and when you want to use the fan or not..

Since you have a Harman, they are really overbuilt...I wouldn't be concerned with damaging the stove.. The one Harman that had a bad baffle, and cracks on the sidewalls where the baffle was welded in, that was the subject of a discussion on the forum.. It was pretty old, 20 years sticks in my mind, and the stove had burn a lot of wood,, which can be a lot hotter than coal if not controled..

What I mean is that a good load of wood in a stove, and the door left open will turn the stove cherry red faster than a load of coal with the door left open.. I have personal experience with a cherry red wood stove.. it only took about 20-25 minutes,, and it was a much bigger, heavier stove than a Mark II or III.

The Harmans are built like tanks.. I wouldn't be concerned..

Greg L
Stoker Coal Boiler: Axeman Anderson 260
Hand Fed Coal Boiler: Self-built 'Big Bertha' SS Boiler
Baseburners & Antiques: Keystone 11, Art Garland

Re: Mark II Durability without blower ?

PostBy: grizzly2 On: Wed May 21, 2008 8:43 pm

My Hitzer is built for fan or no fan use. It also has a double wall in the back and part of the top. The fan is actually an option. These stoves were orriginally built by and for the Amish, and they use no electricity. Also the Hitzer is only 3/16" plate steel, not 1/4" like your Harman. As the other guys have said, with a little common sense in firing, you should have no problem. :)
Hand Fed Coal Stove: Hitzer 30 - 95
Coal Size/Type: pea and nut/ anthracite
Other Heating: Jotul #3 wood stove in garage. Oil backup in house. Electric backup in house.

Visit Hitzer Stoves