I want a simple to use reliable boiler

I am looking for a boiler that is simple to use and is reliable. Is this a good boiler they say it is 80% efficient I can get slab wood cheap and will burn mostly that. also interested in greenfire boilers will they burn slab wood very good? I currenly have a gas boiler
I want to heat a 4000 square foot poorly insulated house. Any advice is appreciated thank you.

You and me both LOL.....I've been looking around for a few weeks and seems simple and foolproof = low efficient, long burn and heavy on wood use . ie owb. What I'm hoping for is the new generation of outdoor boilers (gassifiers) to start hitting the market. I know they have them but getting information on them is like pulling teeth. I'm hoping it's at least partly driven by a large inventory of the current versions. but I'm a wishfull thinker. Good luck, I'll be lurking on this thread hoping you get some answers.

Greenfire operates excellent with large rounds. Not so good with dry splits. I guess slabwood falls somewhere between the two. Check with Mark at Greenfire but I don't think it is the best unit out there for slab wood.

You referred to two boilers (I think) in your post, unless I'm not reading the first couple sentences correctly. Greenfire was one, what's the other one?

The problem with slabwood is that it tends to burn fast. It can make for overheat conditions rather quickly in some units. A typical OWB will not even come close to 80% efficiency. Most independent tests that I have seen on the major brands shown less than 50% with most in the 30-45% range. Cycling a fire that wants to burn hot and fast (slabwood) will drive efficiency even lower. That being said, if you are going to use slabwood or pallets, you'll have much better results with a unit or system which includes a large storage volume. 1,000 gallons or more would be able to soak up a fair sized load of slabwood enabling you to get by with a couple firings a day. I'd probably mix some cord wood in with the slab stuff if it were me. What area of Michigan are you from?

I am still working out the learning curve on my Greenwood 100, but have been pleased overall. Simple design. Wood in, heat out. As for burning slab, I only know one friend who does this - and it is because he is a post and beam builder and has access to a lot of free slab. He uses a Heatmor OWB CSS 200. He says he can get away with burning slab with this particular unit because it has a forced draft that helps to cut down on the smoke - slab can smoke a lot. As for efficiency, it is an OWB - so less than 50% efficiency, but his wood is free. Trade off I guess. My neighbors are too close for me to even think about burning slab.

Good Luck.

Pete

Central has come out with the E-Classic that is suposed to meet the 2010 regulations, Heatmor also. They don't give much information on how they work, what kind of maintenance is required, burn times, how picky on wood, etc......and I hear there is a few more comming down the pipe.....I called on a few and they are real tight with the specifics, like so tight I couldn't get any. I think they thought I was a spy LOL Or most likely they want to burn off there inventory.