OT - Tarm USA add-on wood-fired boiler

This is quite a bit OT, but I am sure there are many folks here who heat with wood, so...

I have a wood-fired Tarm USA add-on boiler (my second season with it) that was installed to work together with my oil-fired Weil-McLain boiler (hot water heat). When the fire goes down too low, the oil boiler fires up and vice versa.

My problem has been that the wood boiler belches a ton of smoke every time I open the door to add wood. I"ve played around with the three draft controls this thing has but with little luck. I have a fairly new chimney (built 2002, last cleaned this summer) which this boiler shares with a woodstove upstairs. I never have any draft problems with the woodstove.

My wood isn"t top of the line (I harvest all my own) but there is still quite a bit of hardwood. Also some of the wood was cut before I installed the boiler and was cut too long, so I have to stack it vertically.

If anyone out there has any experience with the Tarm units or any add-on wood units, I"d appreciate whatever info. I can get. I"ve tried something called a draft inducer (basically a fan that goes in the smokestack) at my parents" house with their setup with no luck. It gets kind of old to have to open all the windows to let the smoke out. Thanks in advance.

IN STICKS: The boiler did the same thing when new. Yes, there is a lot of creosote built up on the inner walls of the boiler, like I said, I don"t burn the best wood. There is a plate you can take off on top to clean the "heat exchanger". I am also going to clean the pipe connecting the unit to the chimney.

Forist NWMa: My wood has been seasoned about 18 months but right now it"s mostly pine. I am getting to some hardwoods further down in the stack once they season. I don"t have the heat storage tank, no room for it in my 150+ year-old cellar with all the other stuff that"s already there. What draft inducer do you mean? I don"t have anything on top of the boiler.

Matt Kane: It"s a block chimney built in 2002 and it"s about 25" tall (actually, two chimneys side by side). I have my oil boiler, the Tarm and a woodstove, so I have to share the chimney. No, I do not have any grilles in the cellar, the windows are boarded up and have some conduit and pipes running through them.

By the way, this is an older model Tarm, not one of the new "wood gasification" units. Tarm USA tried to sell me one for a lot more money, of course.

Thanks again.

A bigger problem I have is that, when there are red hot coals in the bottom, if I throw in the wood too flat and the air can't get away, it waits a few minutes, goes 'woof' and blows a bunch of smoke and ash back through the ash drawer. So I try to be careful about that.

On very cold days, the back smoke is much less, leading me to believe that it is draft related.

Let me know if I can be of help - I'm no expert, but my eyes have been filled with smoke a time or two.

Good luck,

Bill

the water gets up to temerature, the air in-take damper closes, and the wood sits and smolders, results in less complete burning of the particulates, less heat, chimney gets cooler causes less draft, more smoke into the basement when you open up the door to add wood.

If so, is there a secondary air inlet to the upper chamber? If you shut that off when the door is open, it may improve flow of smoke to the chimney.

I have a similar set-up, but with a very simple boiler (basically two large steel pipes, one inside the other forming the water jacket - with an insulation jacket)not a TARM.

The boiler was built with a solid (i.e., not adjastable) baffle at the smoke discharge hole - it was meant to interfere with the draft so the heat does not go up the chimney too fast - I suppose it was supposed to make it more efficient.

This baffle caused lots of smoke to come out of the door when loading wood, despite the hinged smoke door hanging down inside the loading door. I dealt with this by just opening the door quick, shoving in a piece of wood, closing it quick, repeat .... It minimized the amount of smoke comming into the basement, but also minimized my pleasure in burning wood.

The smoke discharge baffle fell off after a few years (held on by two thin tacked-in-place bolts) and it has been much better since - and I don't think it impacts the efficiency of the boiler at all (not too efficent to begin with).

If you have such a baffle, that would be your problem. Would greatly improve if you took it out.