I've been lurking for a while and thought I had it just about figured out...then the bldg inspector said that anything going in would have to be listed by UL, ASME or some other recognized organization.
Thought of putting a Keystoker KA-6 multi-fuel (coal & oil) in place of the current boiler (112,000 net btu) but the current space is wedged between the base of the chimney and the stairs to the basement and is 6'4"l x 4'9"w. No extra flues. Another thought was to direct vent (there will not be another chimney says the boss) a KA-6 or KAA2 about 18 feet away, plumbed in with the current oil unit. It appears the current boiler space may be too tight for the KA-6, and I don't believe Keystoker has an ASME rating.
The AHS s130 has the ASME listing, looks compact could go into the chimney (not a direct vent candidate) as long as I could move the oil unit and direct vent that (tbd). The EFM multi-fuel would be great, but is too large for current boiler spot where the flue is, and a real coal bin would be difficult.
Does anyone have suggestions of units or configurations that might satisfy the building inspector? I'm thinking of 1) a listed unit that can be direct vented, 2) a compact multi fuel option that can go in the current flue 3) compact coal unit into the flue, provided I can direct vent the current boiler (tbd). I really want to go with coal, but the space in our basement (half of which used as a garage) is quite limited. Thanks in advance.