Brunco Hot Air Furnace

How are they? Anyone have any experience with Brunco? A customer of mine has a Brunco Wood/Coal hot air furnace in the basement. It is a very simple set-up. They have burned wood for the last 18 years, but asked about coal (the subject came up). Seeing I was going to be on the job a second day, I brought a few pails of coal with me. We dumped the coal in the furnace. The coal took off burning nicely. When I left at the end of the day, stack temp was 150*. The coal fire was well established. No issues what so ever. I do believe the home owner is now hooked on coal. They buy all of thier firewood. They might better buy coal. I think that's how the subject got started.

My very first furnace was a Brunco 190. It sure was a heavy beast and well constructed. I found it to be an excellent wood burner but, it struggled to burn coal with. I attempted two years to get that Brunco 190 to burn well with anything but wood. I did not do any modifications to the furnace. What I should have done is take the ash door to a metal shop and have a draft spinner installed. The only air opening to the fire is the draft blower up front that blows the air into the fire. If air was allowed to enter through the ash door under the fire I believe the furnace would have performed much better burning coal.

The metal secondary baffle plate above the fire collected a lot of fly ash. Therefore insulating the secondary chamber and reducing the air flow passage to the flue. Trying to keep that area clean was a challenge because of the metal draft flap hanging half way down in front of the feed door. It would not open all the way up to allow for easy cleaning of the secondary draft passage. The draft blower would forge the front of the fire, clinckering the coal and would not supply an even flow of air for the fire to burn coal nice, even and long.

So I sold the Brunco 190 and purchased a Clayton 1600. In my opinion, the Clayton is a far better design and efficient furnace. But after finding this forum, in retrospect, I would have tried to modify the ash door with a draft spinner, even though Brunco says it will void their warranty. I also would have installed foil backed insulation to the inside of the red sheet metal panels to give a better heat exchange to the duct work. The outside of that furnace got really hot and more heat radiated into the basement that was blown in the duct work.

Another reason I got rid of the Brunco 190 was the fact that it was very difficult to try to install a domestic hot water coil into the firebox. The rear of the furnace has two 1/4" steel plates space out an inch or so and the location the coil would need to be was very hard to drill through and too close to the flue.

Overall the Brunco is a very well heavily constructed furnace, but truly designed for the wood burner in mind. But now with the knowledge obtained from this forum, I know that it could be modified to burn coal much better and longer.

Hope this helps. DOUG

DOUG wrote:My very first furnace was a Brunco 190. It sure was a heavy beast and well constructed. I found it to be an excellent wood burner but, it struggled to burn coal with. I attempted two years to get that Brunco 190 to burn well with anything but wood. I did not do any modifications to the furnace. What I should have done is take the ash door to a metal shop and have a draft spinner installed. The only air opening to the fire is the draft blower up front that blows the air into the fire. If air was allowed to enter through the ash door under the fire I believe the furnace would have performed much better burning coal.

The metal secondary baffle plate above the fire collected a lot of fly ash. Therefore insulating the secondary chamber and reducing the air flow passage to the flue. Trying to keep that area clean was a challenge because of the metal draft flap hanging half way down in front of the feed door. It would not open all the way up to allow for easy cleaning of the secondary draft passage. The draft blower wood forge the front of the fire, clinckering the coal and would not supply an even flow of air for the fire to burn coal nice, even and long.

So I sold the Brunco 190 and purchased a Clayton 1600. In my opinion, the Clayton is a far better design and efficient furnace. But after finding this forum, in retrospect, I would have tried to modify the ash door with a draft spinner, even though Brunco says it will void their warranty. I also would have installed foil backed insulation to the inside of the red sheet metal panels to give a better heat exchange to the duct work. The outside of that furnace got really hot and more heat radiated into the basement that was blown in the duct work.

Another reason I got rid of the Brunco 190 was the fact that it was very difficult to try to install a domestic hot water coil into the firebox. The rear of the furnace has two 1/4" steel plates space out an inch or so and the location the coil would need to be was very hard to drill through and too close to the flue.

Overall the Brunco is a very well heavily constructed furnace, but truly designed for the wood burner in mind. But now with the knowledge obtained from this forum, I know that it could be modified to burn coal much better and longer.

Hope this helps. DOUG

Thanks Doug, that does help. When I arrived in the morning, he had a nice bed of wood coals. Before adding coal, I asked if the blower put air below, or above the grates. I asked the question because the blower is mounted above the grates, but could have been channeled below. The home owner said he didn't know. I tried to feel below the grates, and nothing. The home owner said the ash pan door gasket leaked a little. I'm wondering if that is all the air he is getting.

Yes. that is probably why it is still burning the coal. I noticed when I kept my ash door cracked open, I could burn coal rather well. The only problem I had was that there wasn't anyway to really control the fire temperature to the desired heat output except only at that sweet spot. The sweet spot was when the outside temperature was a certain degree and the heat loss of the house was just right for the amount that the ash door was cracked open.

I'd order another draft spinner and bolt from Brunco that is on the feed door and have it cut in the ash door the same way it is installed on the feed door. By doing that, you'll have a pretty nice controllable coal furnace. The grate system is really good and the firebox can really hold a lot of coal for a nice long even burn. Don't forget to install a barometric draft regulator in the stovepipe or you'll have a heck of a time trying to dial it in to the needed heat output.

Let me know how it is working out. DOUG

Ive been using a brunco forced air furnace for 5 years now .Ive burned hard and soft coal.I think it burns coal excellent.As far as putting a spinner in the ash door would be a mistake.This furnace is designed with the forced draft fan above the fire for a reason.when the furnace isnt calling for heat it idles very well.having to pull the air down ist.If a spinner was in the ash door the furnace would idle above thermostat.As far as a fly ash build up problem on the baffle,Ive never once had that much build up to have to clean it .Sounds like your draft isnt that good.I now burn all bituminous coal in my furnace.It all burns down to a fine ash with no clinkers.I think most people having problems burning bit. coal is the way they load there stove.

Thanks Painter. Always nice to have at least two replies. Last I talked to him, the fire was going 1-1/2 days on the same three 5 gallon pails we originally dumped in for the first bed of coals. The home owner says to me "Do you know how much wood I would have run through this furnace by now?"