Harman Mark III

Well,
I've finally got the stove up and running for the season and I must say this thing really kicks butt. I fill it once a day and shake it down twice a day. It doesn't get any easier, except for when my wife shakes it down for me so I don't have to. I live in a 200 year old three story New Englander with my stove in the cellar and the entire house is a toasty 74 when it is in the 20's at night and 40's during the day. This is with the stove idling at about 1.5 turns. My son will look in the cellar at night with the lights off and look at the blue flames dancing across the top, and says its cool and reminds him of Northern lights.
Tom

Tom--

Let us know in a week or two of continued use how the Mark III is working for you. I've owned a Mark III for 3.5 seasons selling it last winter for a SF-250.

The stove would tend to go dead around the edges of the firebox due to poor draft circulation or I should say, a stronger draft thru the center of the box. Let us know if you experience this problem. I did. I drilled two .5" holes in the ash door 1.5" in from the sides to try and get even burn. It did work better. No damage done as one could easily plug the holes with a cap screw and nut.

Hi, I am new here, just joined... I also have a Mark III, and this will be the 3rd season now. I burned stove coal in it, the very first year, and it burned good. I had klinkers, and some large chunks of ash, but not that bad. The 2nd year, I burned the same, but got it from a different place. Needless to say, it was bad coal. It had lots of shale in it, and I had problems with large rocks or unburned coal getting stuck in the grates. I had to keep an eye on the fire all the time, because I never knew when I would get a good hopper full, or a bad one. First year, I burned approx. 3 ton of stove, and it lasted the whole winter, and kept the house at 70 degrees. Last year, with the bad coal, I went through all but 5 ton that I got. I was hoping to have some left over, but that did not happen! I had about 1/3 rock in my ash, and had a hard time raking the grates. I did have some unburned coal, but not too bad. This year I decided to change to a smaller size coal. After all the Mark III can burn a few sizes of coal, not just the stove coal. I decided to get some PEA coal this year, and see if it will do better for me. I did not like fighting with the raking part of it, as I did this last year. It was still warm out, but I decided to fire up this new coal, the pea I just got. Got a good wood fire going, and started to fill up the hopper with the pea coal. I had some very small pieces fall into the ash pan, when I first loaded the hopper, but it was very, very little. Way less than I honestly expected. I got a good fire burning, and filled up the hopper. I think I set the screw (draft) at 2 1/2 turns. I work 3rd shift, and I come home in the middle of the night for lunch break. So, I cam home, and checked the fire. It was burning real good, and not in need of anything. I think I did turn the draft to 2 turns though... To make a long story short, I left the fire go out.... but it burned a good 14 to 15 hours on that one load. I had an even burn in the hopper, and the edges were totally burned as well. I think the smaller coal makes a difference. It will tend to burn the coal faster, at the front of the grate, by the screw draft, as that is where the air comes in. But I had a complete burn, with no, or very little waste. It was completely burned, and mostly ash in the ash pan, except for some unbrned coal, from when I raked the grates. I rake my grates gently, and until I see some red ash coming down into the ash pan. When I begin to get the red ash, then I stop raking. Hopefully this load of coal will do me good this year. I would say 50% of the problems people have, is getting bad coal, or the wrong size coal, then the other 50% comes from not regulating the air correctly, both draft, and flue, or damper control.. I have both an in pipe old fashioned type pipe control, as well as the automatic one, that has a weight on it that can be adjusted to fip open and closed.. I use the hand damper when burning wood, and the automatic, for coal. Like I said, I think this smaller coal burns way better than the stove coal, I have burned the past two years. As long as the coal does not fall through the grates, I think it burns more even than the stove coal. ANother thing, is to make sure that you have a high enough chimney, to get a good draft. Ok, thanks for your time..... When cold weather finally does hit, I will be sure to let you know how good this coal (pea) really does, after burning for a few days, or week.. See Ya!

Well, I'm reporting back on my Mark III. With the temps in the upper teens at night and temps in the upper 40's to lower 50's during the day I am getting about a 16 burn with my stove set at 1 1/2 to 2 turns. I'm heating the cellar, (only because that is where the stove is), and the first and second floors of a 200 year old colonial. The temps in the house have been hovering right around 72-74 around the clock. The only problem I was having at first was my stove would keep going out when the bed got low. What I found out was I was starving my stove of oxygen to burn. My house is wrapped really tight and with the oil boiler going for hot water and the coal stove going to heat the house it left very poor air plus poor draft conditions. I ended up cracking a cellar window and this made all the differance. What clued me onto this was my oil boiler would sound like it was really working hard for the short periods of time it would run. Now with the window opened it sounds much better and I'm getting a more complete burn with my stove. Now that I have this all sorted out I'll be hooking up a hot water heater to the stove. I had installed a heat transfer coil in the stove before firing it up. As soon as that is in I'll report back on that.
Tom

Rouxy...good to hear that you figured it out! Itsw amazing what patience and a watchful eye/ear will do!! Everyones fire and stoves are different...It just takes time and observation...and that part I love!! Dave

Hello I am in my second year of burning coal with my Mark III. My home was built in 1860 and I am heating 3,300 Sq ft. last year I went through about 5 ton of nut coal. I shake down and load my stove every 12 hours. I kept my air control open 1 turn last season, and filled my stove to the top of the bricks and it would last 12 hours no problem. When I go to shake My stove down I first sprinkle coal on top and then I open the ash pan door to shake down. I noticed that the new coal is fired my the time my shake down is done. Then once my stack temp is at 300 or above I close my ash pan door and fill it up. My stack temp will drop down to 200 and stay there. if it is sub zero my temp could get up to 250 at 1 turn on the air control. My basement is not tight and neither is my house. My basement stays between 75 to 80 deg. my first floor stays at 72 and my upper level is nice sleeping temp of about 67. This year I am using a wood stove insert in my fireplace to supplement. I turned down my coal stove to a little more than 1/2 turn open. I have a great draft and I fill the stove to a little above level from the front bricks. My basement is maintaining 72 deg and I get about 2 1/2days to 100 lbs. of coal. On 20 deg days I use the wood stove to supplement and I go through about 12 log at most per 24 hrs. I'm also interested about getting a hot water coil for this stove to help cut my elect. bill I look forward to more info about this. I really enjoy burning coal!! My new motto for heating is
COAL IS KING

Well, Got great news and not so great news on the water heater coil set-up. Got everything hooked up and the thermo-syphoning thing really does work. I'm getting free hot water and I mean hot. When taking showers the hot water is now turned way down. So this is great. What isn't great is the hot water tank, an old one, starting leaking just a little after about a week. Well, about 2 days after that it starting leaking alot. Fortuneately I had installed isolation valves when hooking it up so with just a quick turn of a couple of valve and the tank is disconnected from the water system. Now I have to replace the tank. Other than the tank leaking the system does make alot of free hot water. It is well worth it to me.
Tom

how do you like your mark3?...i bought a new tlc2000 this year and very unhappy with it,it doesnt radiate heat from the sides,so i called my dealer and he is going to give me my purchase price towards a new mark3...very good of him i thought.now...just waiting 2 weeks for delivery.it has dipped into the teens here at night and i had to turn the oil up just to stay warm....i have the stove in the basement heating a single story ranch

Bugize, I like my Mark III alot. I have a 3 story colonial with the stove in the cellar. The house has many additions through it's 200 year existance so it is a differant experiance to move the heat around to the many differandt places. But, the stove does put out some heat even when the temps nose dive into single digits my house stays 72 - 74 in the first floor. My cellar is always very warm which keeps the upstairs floors nice and toasty. What I did do that made a big differance in moving the air around was hook up a cold air return to the blower in the back of the stove. That way colder air is pulled from the upstairs which is then replaced with the warmer air from the stove. Harman says you can burn many differant size coal but my experience has taught me that pea coal falls throught the grates. I feel that nut and maybe a size larger for the coldest of days works the best for me. But then again I run mine between 1.5 to 2.5 turns whereas most people I've talked to run between .5 and 1.5 turns. You will like the Mark III, it does put out some heat and the stove is well built. It is very heavy but the doors come off without the use of tools to help transport.
Tom

hey Tom,i just noticed your not far from me,probably experiancing the same temps. that was a good idea to hook up a cold air return on your blower ,i had to run my tlc more open than most others,so i mite have to run the mark3 around 2 turns out,do you run a hand or baro damper?...i put one in for my tlc but i dont think it did anything so i left it open all the time. i will be burning nut in it so i should be fine

I use a barometric Damper on my Mark 3 and it works great. Initially I didn't have anything, and on really windy days my burn time was significantly shortened. Once I installed my Baromertic damper (per manufacturers recommendation) the stove burned at a constant level regardless of any increased wind.

Rouxzy, Did you purchase this coil from Harman and drill your stove yourself or have it done. What is an estimate cost for this type of setup with the exception of a water heater? I'm really glad to hear that it is working well for you. Do you feel that you have hot water to spare and what size water tank are you using. I also prefer using nut in my stove.