will there be a payback

Kevin Shaw

Guys,

I have a 1924 center hall colonial home in upstate NY 2800 sq ft. The current system is original HB Smith coal boiler that was converted over to natural gas. It is a hot water system that has no pumps it is all gravity with cast radiators. I am thinking of replacing it with a Dunkirk Q90 100,000 BTU condensing boiler. The current system has 2 pipe radiators and the boiler has 2 supply lines and 3 return lines (2 of them tie into one at the boiler). Do you guys think it would be best to run 3 pumps on the new system? The lines to the radiators are 3 inches in diameter. There is no good way to zone the current radiator layout as the front of the house (all 3 floors) are on one loop and the back half of the house is on a second loop. All of the dedrooms are on the top floor so I think I am stuck with one zone. When I do the heat loss calculations I come up with 87,000 BTU which is why I am leaning toward the 100,000 BTU replacement. Do you think I will lower my natural gas bills by making this investment? How much do you think I will save? How much does the new boiler cost?

kevin