Harman Mark II - how oftern will I need to feed?

Hi, I'm thinking about purchasing a Harman Mark II.
We have a cape cod style house in New England and the total square footage is about 1700sqf.
Until now, we used Vt. Casting, Vigilant to burn the coal but it's an old style and not very efficient.
Could anyone tell me how often I'd need to feed Mark II? Once or twice a day?
The company's brochure says it can run up to 24 hours, but is it really true?
Thank you!!

You can go 24 hours with low output. 12 hours is the common practice.

The Harman stoves are well built but lack a thermostat and hopper which make life a lot easier.

welcome to the FORUM s--franco b pretty well covered it--enjoy.

welcome...before u buy check out the hitzer models...just type hitzer stoves in the upper right corner google search block

I have a Mk II in a "raised ranch" style house in RI. The biggest issue I see for you is getting the hot air where you want it.

Otherwise, the Mk II will be as good as any stove you can find.

I COULD go 24 hrs on one tending at "moderate" heat levels but every 12-ish hours is more realistic.

At LOW output, my best on this stove is over 30 hrs.

I have a Mark II. 300 deg stove temp and below I easily get 24hr burn time. So far this year I have only been tending the stove once a day.

Thank you very much everyone for the quick responses!!
When you say "low output", what is the surface temperature on the stove with one feeding a day?
And what are the surface temps for the "regular output" and "high output"?
Thanks again!!

I really ought to get a thermometer but right now I'm using the tactile method(my hand)

"Low output" to me is if I can lay my hand on the stove for 30 seconds to a minute. Surface temp of no more than 125* at most.

My normal temp is where I can touch the stove top for a quick 3 count. And I can touch my stack pipe before the baro for as long as I want. Again, no more than 125* stack temp. I run my room temp at 70* in any outside temp.

Seavs,
I have a Mark iii in a 1900 ft raised ranch, stove in basement. Depending on the outside temp, low for me is 300* and when I want the upstairs about 70* or so the temp is 500-550* using a mangetic thermometer placed on the side of the stove not on top. also I have a MPD and after the blue ladies show up, I close
about 75%. The Reading coal i am using this year I shake three times a day. Will not use again.
Cracker.

Mark III here - 24 hour burns are the norm since switching from Kimmels bagged nut, to Blaschak - same size. The Blaschak has so much less ash that there's no need for a 12 hour shakedown. With Kimmels, I didn't have a choice, since the fire was being snuffed out by hour 10.

seavs wrote:Hi, I'm thinking about purchasing a Harman Mark II.
The company's brochure says it can run up to 24 hours, but is it really true?
Thank you!!

It's a little like gas mileage claims.
When something says "...up to..." that means that, yes,
you "CAN" get that. But you probably won't...

For the most part, unless you are WAY off, there is X amount of heat
per pound of coal. So it depends, like others will tell you, on how much
heat you need to stay warm.
I have a Mark III.... I can make it go 24 hours.
As long as I'm not interested in staying warm.
If, when it's 3° and the wind is howling at 20mph, I'm putting coal
in that baby every 10-12 hours. With the side of my stove at ~575°-600°.

But. What I prefer doing, is putting smaller amounts of coal on,
maybe every 6 hours, just to avoid any big drop in temperature,
due to covering a smaller fire, with a large amount of coal.

Dan

Yep - in January I'll get 16 hours with 700° sides. Hotter you burn, quicker it's gonzo.

Thank you so much for all the helpful hints.
I have one more question for you guys....
If you can get away with one feeding for 24 hours, does it mean you only have to clean the ashes once a day as well?
Or do you still have to clean twice a day?
If you only feed once and clean once, do you still need to shake a several times during a day?
For my current Vt. Casting Vigilant, I have to feed and clean the ashes twice daily, but I only shake during the cleanings.
I'm wondering if the frequency of the feeding equates to frequency of the cleaning....
As for shaking, do you have to poke the coal with a metal poker before shaking?
For Vt. Casting, I have to poke before shaking....
I'm sorry for so many questions.
Thank you!!!

If I idle my stove for a long time (>24hrs) then I find ash builds up in the corners and along the front wall so I will poke it to break all that up to ensure it all shakes out.

As a rule, I fill/shake the stove at the same time. If I'm in a rush, and the fire looks healthy, I'll just pile some coal in and shake it really well the next time I fill it.