beatle et all: thank you for referring me to AHS, I did come across their website in my searches but didn't know they were worth the look. It appears their products are also certified, so it may be an option.
Potentially dumb question if you guys don't mind: since I'm planning to run coal boiler in parallel with existing oil one, wouldn't it be easier to just install a dual-fuel boiler like the one AHS sells (http://www.alternateheatingsystems.com/ ... oilers.htm
) and get the best of both worlds? Are these much more expensive, or much less efficient then two separate boilers (oil and coal, in my case)? Any reason why these are not a good alternative then parallel setup?