Size of Modulating Boiler and Efficiency

[JeffQ789]

Hi,

We are considering two options for heating our home (a 100-year old, not very well insulated 2,100 square foot house near Chicago):

1. The Utica UB95M-200 modulating condensing boiler.
2. The Weil McLain Ultra 155.

The Utica modulates from 80 to 200 MBH, and is rated at 95% AFUE.
The Weil McLain modulates from 31 to 155 MBH, and is rated at 93% AFUE.

The Weil McLain will cost about $xxxx more than the Utica, because it requires two pumps, rather than one, as well as primary and secondary piping, and is not eligible for the $150 tax credit (since its AFUE is below 95%).

Our estimate is that our house at most requires something in the range of 100 to 125 MBH, so we would probably never need to operate in the upper part of the range of the Utica. My hunch is that the Weil McLain might be more efficient, since it can modulate to a much lower level (which might be appropriate when it is only moderately cold here).

Given this, would you expect that the Weil McLain would run much more efficiently (despite the lower AFUE, which I understand might not be that representative of actual performance)? If so, would you recommend it or the Utica?

Thanks,

Jeff

[beenthere]

The Ultra will do less short cycling at the milder outdoor temps.

My vote would be for the Ultra.

[gsxr]

Ultra also