Martin, glad to see North American mfgs finally adopting European design in wood combustion. However these do need more attention and maintenance. I was going to build on in this design, but after seeing a Garn in operation my mind changed. Starting my 15th year on my home built and never looked back. Can burn -40 to 100*f and it doesn’t burn any different. No creosote, horizontal flue, water storage built in, minimal parts. If someone has the space and up front capital, they are an awesome boiler.

Martin, I'm getting stuck turbulators on my G4000. I believe Creosote must have accumulated somehow and locked them up. Stove was doing fine heating the water. I left on a trip and my wife was adding the wood. She informed me the temp dropped to 78 deg with a fire in the firebox. Best I can figure, the turbulator tubes are clogged as the cleanout handle won't move.

I'm just curious. Wouldn't it be better to have the fan on when you open the door and not have any trap door at all so the smoke could just follow the normal path down and not worry about cooking the fan?

You said 20.3 O2 reading what if it's higher? I get 25 in the stove when it's not burning I can't imaging there would be more O2 inside thn outside.

Martin or anybody please what’s the cost for a unit like this one Thanks