What Size Boiler?

Cohiba8250 wrote:It would be worth spending more on the boiler if it's coal consumption was less.

Once you get into the pricey stoker boilers, the difference in what they burn isn't going to be big enough to even consider. The installation will probably have a lot more impact on how it performs and economy of operation than who made it.

Find an excellent used or re-manufactured boiler, any of those mentioned will work fine, the cheaper the better. Take the money and spend it on a great chimney and plumbing. Even a twenty year old coal boiler is going to have a greater life expectancy then the liquid and gas units coal competes with.

Cohiba8250 , If you want to see a keystoker running you are welcome to come over to take a look . I had a hard time buying something without seeing one run . Dave

The KA-4 and KA-6 appear to use the exact same stoker, just the boiler size is different. You might end up with better efficiency on the KA-6 due to better heat transfer to the water due to the increased surface area. I'd guess they would both idle at the same rate, so that shouldn't be a big difference.

I heat about 4,000 Sq feet of poorly insulated, drafty, old 1910 wood house that gets a direct west wind off Lake Erie with an Axeman-Anderson 130 and 1020 sq ft of old cast radiators.

It does pretty well except on a windy sub zero day, but there aren't many of those.