We have a 23 year old HeatMaker Plus combination heat and hot water unit on its last legs. We have an interior (not an end unit), two-story VT townhouse (built in 1986-900 sq ft) with a simple, single loop baseboard system. Propane. The dedicated boiler room is 4' x 7' with a horizontal vent (8' high). Municipal water supply (7.8 ph, 6 GPG).

We've spoken with four contractors (all recommended by others) and are having trouble deciding on the smart replacement.

We have been told basically two options:

A) Laars Endurance 110 combi. Cheapest solution. Successor to HeatMaker. Most of our neighbors have gone this route. Replacement quoted at approx. $5k (possibly $4k if we source unit ourselves). Will realize some fuel savings with the newer unit. One contractor felt that the unit was not especially reliable. Unit carries 20-yr warranty.

B) Triangle Tube Prestige Excellence 110 combi LP. Net Replacement cost of approx. $5500. ($7k minus $1500 tax credit.) Only 10 year warranty. More efficient unit, but one contractor felt that actual difference in savings performance would not be dramatically noticeable. Said 95% efficieny ratings were not real in terms of actual performance for our system, said we'd probably run more in the 80% range.

Two questions:

1) Which of these options would you select?

2) Are these the only two options? What about a single high efficiency wall hung boiler & tankless water heater? The space seems large enough to accommodate the two units, but perhaps they couldn't be vented properly.

Eager for some insight . . . .