My best friend still has the original furnace in his 2200 sq. ft. full basement house in CT, a 122,000 (gross) btu unit with domestic water coil, baseboard hot water. The unit runs ok, but my sense is that a modern unit might pay for itself fairly quickly with $2+ per gallon fuel oil he is buying. The current unit was installed in 1987. Buying a state of the art unit today 1.) What should he expect to pay ballpark and 2.) what kind of fuel savings (%) should he expect over his now 18 year old unit? One installer recommended a Buderus, but wonder if those extra $ really pay back.