Wood Fires in Harman Mark*

Pardon the 'heresy' on a coal board, but I could not help starting this thread based on Greg's comment from another post:

Anthracite is recommended, but the Harman Mark stoves do a good job with bituminous coal as well as with wood

I've been wondering about going strictly wood when it gets cool instead of COLD (I've got about 3 cords from an old maple that needs to burn sometime..) Harman forbids anything other than coal (except when lighting). But they also forbid MPDs and we know some folks have those attached to them.

Obviously Harman likes the CYA approach, they're big on 'forbiding'. So my post goes toward the discussion of why not wood? If it is well seasoned, the brick-lined burn chamber looks like it wood be fine for wood (though my Mk1 would mean small logs). Is there mainly a concern if you burn wood for a while, and then switch back to coal could cause creosote fire issues? Just curious on peoples experince burning wood in these appliances. Thanks, Trey

Hi Trey, my only concern is being complacent about a clean chimney. Since coal only makes fly ash, we could forget about the dangers of creosote buildup. Otherwise I see no reason to not burn wood, especially if it is good, dry hardwood.

When you switch back to coal, the dry heat from the coal fire often makes the creosote fall out of the chimney in sheets, so be aware of potential chimney blockages.

Personally I'd use wood durning those days when you are around to tend the fire, load it often and keep the fire HOT. this almost eliminates the creosote, which is the smoke from partially burning cool wood fires. If you use the wood during the warmer months, you will have to cut back the air to the wood, which will make it make smoke and creosote...

So I'd burn wood on the days/weekends that you are home and burn short hot fires of 2-3 hours for each loading, Then use coal during the long nights/days when you aren't around to feed the fire every few hours.

Greg L

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I would rather continue to burn coal and cut the air intake way back, and adjust the windowstat accordingly. I've had enough with creosote build-up in that chimney. Or I could just let the stove go out and run the wood burner instead.

I've burned a lot of wood in my Harmon. I think its easier to burn coal, but I have a lot of blow downs to get rid of. You're right, usually I use it during the cooler, rather than COLD times of the year when I don't care so much about the fire going out through the night. It works nicely in late fall to take the evening chill off and build up a little heat in the house to carry through to the morning until the sun can warm things up through the day.

As others mentioned you need to pay close attention to your chimney when burning wood. Ours is an insulated double wall SS only going up 1 story, so it doesn't allow the gases to cool much on the way out, as a result I don't get the creosote problems. Your set up will probably act differently than mine.

Wood'nCoal wrote:I would rather continue to burn coal and cut the air intake way back, and adjust the windowstat accordingly. I've had enough with creosote build-up in that chimney. Or I could just let the stove go out and run the wood burner instead.

"adjust the windowstat "........ROFL...I like it!

I have a Mark II and I burn wood in it quite a bit. It does a fair job but it likes coal better.

I think the main reason Harman doesn't say you should burn wood in the Mark series stoves is EPA. The emissions without the catalytic system on a woodburner probably prevent them from meeting emissions in some states/counties. So they can't say it's a woodburner and meet the regs. But I hear they work good, and my home-made stove, patterned of the Mark III, works good for wood too. I burned wood in it for a week in October before I got the nerve to try coal in it.

Steinke

Exactly - the EPA. If you read the large metal plate on the back of the Harman you will find a statement that tells you that you are violating "Federal Law" to burn anything but coal, unless it is for igniting purposes. So much for a "limited" Federal Government!

All-
Thanks for the feedback. I guess it comes down to creosote buildup as the only real concern, which is not an issue for me (I have an exterior cleanout door on my block chimney - could not be easier to brush out)

Kind of a side note here, regarding the wood fires. I have had to re-light my coal fire 4 or 5 times since I bought it around a month ago (ok, I'm still learning..) Each relight I got alot of paint/chemical smell while cranking the wood to get a coal bed ready. Last time I cheated and used some grill charcoal and no smell, but much quicker time to light the coal, too. I would have thought by the first 1-2 firings that my factory paint would have been cured? How long until that smell finally leaves? (never have it during normal coal burns)

treysgt wrote:All-
Thanks for the feedback. I guess it comes down to creosote buildup as the only real concern, which is not an issue for me (I have an exterior cleanout door on my block chimney - could not be easier to brush out)

Kind of a side note here, regarding the wood fires. I have had to re-light my coal fire 4 or 5 times since I bought it around a month ago (ok, I'm still learning..) Each relight I got alot of paint/chemical smell while cranking the wood to get a coal bed ready. Last time I cheated and used some grill charcoal and no smell, but much quicker time to light the coal, too. I would have thought by the first 1-2 firings that my factory paint would have been cured? How long until that smell finally leaves? (never have it during normal coal burns)

I have the Mark III and built several hot wood fires that cured the paint, leaving several windows open during the 3 day span. No more paint smell after that.

I have Mark III and I burn a lot of wood in it in cooler weather, when it's cold outside I switch to coal. Personally, I like to burn wood in it , I have no problem, just keep ashpan door knob closed , Loading door has openings for air intake and it's enough air for wood. I can keep it fir up to 10-12 hours with one load of wood (up to the top full by white ash or oak)). With Wood it's good idea to put mag thermometr on pipe to maintain temperature high enough to prevent creosote build up and regullary check chimney top cover net, becouse of creosote (I have to clean once or two per season ,just knocking by stick or screwdriver. Guys above right: Harman with wood has a lot of emission,so...,they protect themselfs. Good luck with wood.Serge.

spaserg wrote:I have Mark III and I burn a lot of wood in it in cooler weather, when it's cold outside I switch to coal. Personally, I like to burn wood in it , I have no problem, just keep ashpan door knob closed , Loading door has openings for air intake and it's enough air for wood. I can keep it fir up to 10-12 hours with one load of wood (up to the top full by white ash or oak)). With Wood it's good idea to put mag thermometr on pipe to maintain temperature high enough to prevent creosote build up and regullary check chimney top cover net, becouse of creosote (I have to clean once or two per season ,just knocking by stick or screwdriver. Guys above right: Harman with wood has a lot of emission,so...,they protect themselfs. Good luck with wood.Serge.

i burn almost all wood in my mark III and get 10-12 hrs. the thing puts out a lot of heat.

with a mark I you'll be very limited on how much wood you can put in. if I were to guess you'll only get 4 hrs or so from a load. I looked at a mark I for wood and though it was way to small for what I wanted it to do.

imho the only thing a mag thermometer is good for is to tell you how hot your stove is.
it isn't even close to what's going on inside the flue.

i've seen over a 200º difference on a mag over a internal.

Glad to see others are having success burning wood in the harmans. One of the reasons I bought my sf150 duel fuel was that I want to burn some wood in the late fall early spring. I was thinking of selling it when I got a deal on a vf 3000 but I have to run it for awhile before making a decision. If it will crank burning both i'm keeping it.

Salemcoal wrote:Glad to see others are having success burning wood in the harmans. One of the reasons I bought my sf150 duel fuel was that I want to burn some wood in the late fall early spring. I was thinking of selling it when I got a deal on a vf 3000 but I have to run it for awhile before making a decision. If it will crank burning both i'm keeping it.

at home i'm running a vf 3000 and a sf 150 on wood. the only thing with the 150 is it's easy to build up creosol.
the 150 is too good at removing heat from the flue.
although it's been a lot better since I went with internal thermometers on the flue pipe.

I have a Mark II and have burned wood in it, buts its definitlely not like burning it in a wood stove. I cant get a steady flame because
the air around the glass. I have a friend that has a Harman insert who just ran out of coal and now is burning wood. He was experienceing
the same problem with an eratic fire, so he took out the gasket around the glass which is not a full gasket and replaced with a full one. Problem solved,
now he uses the air screw on the ash pan door and has much better control. The only draw back is when he throttles it down at night for a slow burn the glass
gets a bit sooty but cleans up with easy off.