Jay Breckheimer

After some re-measuring. Turns out I have a 3" inside gap between top of burn stack and inside top of barrel. So that should help. A little. I have had 2 burns since I wrote this post. Everything seems to be working fine now. Better each time actually. Thank you for all the input. It helped a lot! I will post some better pics once I get the build complete.

Satamax Antone wrote:2 Inches top gap is way too small for an 8

So you are saying that this diagram that I followed exactly from Ernie and Ericas book is wrong?

thomas rubino wrote:Hi Jay,Welcome to permies!

We need better pictures and more info.     What I can see is) it appears your feed tube is only 3 bricks tall ? That's only 12-13" tall, should be around 16". If it's too short the fire will want to draft up it, instead of your riser. How long is your burn tunnel roof ?   Should be around 12"
What is your chimney like?

Feed is 16" from top to bottom of burn chamber. I went off Ernie and Ericas design with fire brick. Followed it exactly. Can the feed tube be too high? Wouldn't mind adding a piece of chimney liner to the top.

Eric Hammond wrote:As Caleb suggests, it HAS to be a chimney issue or clearance issue between the "barrel" and heat riser.  The current barrel situation in the picture is terrible.  You need to be able to get in there and inspect/clean.  You've basically made a permanently installed barrel.  What did it look like before the barrel was installed?  If the chimney is ok, that barrel needs to come off.

The clearance is 2" between heat riser and top of barrel. The barrel is exactly the same outside diameter as a 55 gal. Drum. Plenty clearance around sides. Over 3". The top of my barrel is getting cut off for access. A barrel band fits perfectly and clamps down perfectly also. It will have gasket rope between. The reason for using the tank was aesthetics. Wife didn't want 55 gal barrel.

My old wood stove that sat here. Exited the same hole and went up. I did not want to go so far up. I had a East wind yesterday blow in right into the pipe, and it just could not catch a draft even when I added an elbow. It worked great today with a NW wind.

I believe the answer is to abandon side outlet and run class A right through the roof as much as I didn't want to do that.

Put a lot of work into this 8" rocket mass heater. Did it all bay the book. Built the fire Box opening and burn chamber 7"×7 1/2". Used refractory kiln brick for the riser 48" high. 250 gal tank 22" wide 50" high. Have 25' of horizontal pipe in the mass set at 1/8" per foot rise toward outside 5' riser 3' horizontal termination to the outside. Holy crap what a horrible back draft! Had to have hair dryer on high with the feed all but closednup around the hair dryer to get it to draft. 15 minutes, removednhair dryer and POOF! Filled the house with smoke. What's up? Help please!