Mark Kansburg

Same issue still continuing. I bought some kiln dried wood to test my wet wood theory and have been burning for almost two hours now. I still end up needing to push it into the horizontal part past the feed tube to prevent smoke back. I finally installed my probe thermometer on the barrel and although it's not measuring the hottest temps which are in the center it is still staying between 900-1000 degrees since it got up to temp.

If anyone has any insight or any idea what else could be the problem please I really want to fix this

So I tried splitting some of the wood even smaller and stacking it pretty tight together like you mentioned. It worked as the fire was in the front of the bundle (front being towards the heat riser) but as soon as it spread towards the middle it started burning up again and pretty serious too. So I tried to think this over and here are the possible reasons I can come up with:
I need to do more of a primer fire to get the temp in the heat riser up to create more of a draft
My wood is too wet and not seasoned enough to burn hot enough to create a good draft
At the bottom of my chimney on the outside of my house there is a clean out but the door is broken and all I have over it is a rough piece of slate
My burn tunnel is too long (doubt it but still) I have 4 half barrels on an 8" system
My COB is still too wet and is sucking up too much heat to prevent getting a good draft at the exhaust, along with any of the above.

This could also be a combination of any of these issues but this is just what I came up with so far. Any ideas or comments would be greatly appreciated.

Still getting succesful burns overall but I am still having some slight problems with the fire going up the wood and eventually leading to some smoke going into the house. Much better then before but still something I'd like to eliminate. I am able to control it though by pushing some of the pieces down into the horizontal part of the unit. I know my wood is not dry enough because I can hear the moisture sizzle off some of the pieces, plus my mass is still very much wet, but is there anything else I can do to prevent this?

Success!!! I got everything going and burning properly. Still not as much of a roar as I have seen on other successful RMH's but none the less. It took a bit to get going but once it did I had no smoke back and all the wood burned sideways like it should have. I only had a short fire, about an hour and a half, because it started doing too good of a job and got the house a little too warm. It looks like the main issue really was just getting a proper seal on everything to get a good draft going through the system. The interesting thing though is that my exhaust temps didn't go above 90 and I still had success.

Hi CJ,

Sorry my wife said I had to finish my son's new room first before I could keep working on the RMH. His room is done now so today I plan to make the extra cob I need to fill everywhere that's smoking and then I'll try again with a quick newspaper only fire and see how it goes. Hopefully I won't have any other smoke leaks in the system. I'll try to post some pictures this weekend but I'll do that in a new thread

Did some more trouble shooting and got the barrel cap to fit better. Did a small test fire with just newspaper and found out that I must have shifted the barrel around too much while trying to seat the barrel cap so the cob around the barrel moved and I'm getting a bit of smoke from there. Also the cap on my ducting for my clean out apparently isn't holding a tight deal cause I am getting smoke from there as well and I have no way of accessing that until the cob dries because I put up a temporary wall to keep the cob flush with the front. Gonna trying jamming some cob over that and picking it away later. Hopefully this fixes my draw issues

Hi Al,

Thanks for the insight. I didn't know that about the fan creating a stronger chimney. As for contacting dragon heaters I did after I posted here as I found a major problem. The gasket between the barrel and the barrel cap that they sell is not working and is letting smoke out. I didn't notice this during the hotter burning because it was able to perform the secondary combustion so it must have been nearly clear but as I was letting it die out o boy did I notice the smoke start to billow out from between the barrel and the barrel cap. So I called right away and honestly did not receive the greatest customer service claiming that I needed to cut the width of the gasket before installing it. I'm sorry but I was already put of slightly by receiving a product with absolutely zero instructions but now I am told that I had to trim the gasket? Why sell a product of it isn't even the correct width for its use? I will be calling again tomorrow when everyone else is in at the company and asking to speak to someone in charge because this is very disappointing so far.

I tried out the fan idea today. It worked pretty good for the first 15 minutes but then the fire started spreading up the wood while still burning sideways at the bottom and thus cause it to start smoking again. Am I doing something wrong? I can't keep letting my house get filled with smoke every day. By the way my entire system did heat up, I could feel it on the clean out cap at the far end, and my exhaust was around 90-100 degrees. Also I am using a dragon heater 8" core with their heat riser and I added 2-4" of clay slip/perlite around the core but not the heat riser for extra insulation. My transition has a CSA of around 120 sq in and I am using half barrels for my ducting, just thought I'd add some more background info.

So I'm done laying all the cob down for my first rocket mass heater but I have a pretty big problem. Two days ago I had the cover over my nice dry seasoned wood break off and had it get rained on all night long. I tried burning to start drying out the cob but it all started smoking back badly. The only way I was able to stop the smoke is to place a cinder block over the opening and let the secondary air intake do all the work. This worked but not to well the fire burned kind of slow and I only got a low rumble not the big roar the rocket should give. I am going to be building a new storage area for my wood next spring but obviously this doesn't help me now. Is there anything I can do to still make this wood work? I was thinking about supplementing with some wood pellets but not sure if that would help.

Hi all,

So my RMH build is finally underway but no matter how much I look at it I just really don't like the way the steel drum looks. I wanted a way to cover it but I know it still needs to give off heat. So my idea is to push cement board a few inches away from the drum and then tile the cement board. I think that this should be enough to prevent any high heat from reaching the cement board and damaging it. What do you think?