I purchased one of those Bucket a Day water heaters last fall that are advertised on Ebay. The shop is only 10 minutes from my home and he fit in the hatch back of my Suburu Forester with no problem. We heated our DHW heated with an oil fired boiler but I decided to go 100% coal. Momma wanted some hot water when it hit 95 day before yesterday. I told her I would try and if I had problems with the chimney getting a good draw I might have to hook the oil boiler back up.
I crumpled up twice the amount of newspaper, added some sticks from the woods behind our house and lit the little puppy off. Not a bit of smoke in the basement and when I shoveled in some buck size coal from Keystone Anthracite caught with no problem. In fact I had to close down the manual pipe damper to slow the fire down so all the heat wouldn't go up the stack.
Our little heater looks like a small version of R2D2 from star wars and we couldn't be happier with him.