In fairness to all, we don't discuss pricing on the Wall. Thanks for your cooperation.
Hydronic Replacement Boiler Sizing
I am a homeowner. My 10 year old Weil McLain Ultra 230 Series 1 has a leak in the heat exchanger. WM will provide a new heat exchanger at no cost to me for the part plus the cost of labor to change it. I have been unhappy with the reliability of the WM and will be replacing it with a Burnham Alp Boiler.
My questions relates to the size of the new Burnham Alp Boiler. The heating contractor has done a heat loss calculations based on measurements. The heat loss is 197,000 BTUH with an indoor temperature of 75 when it is zero outside. Fuel source is natural gas. Domestic hot water is a zone going into an Amtrol 110 gallon water heater. We are debating between the Burnham ALP 210 and ALP 285. The contractor is leaning toward the 285. My view is that the 210 is undersized and the 285 is a bit oversized. I am trying to understand the ability of unit to modulate itself to the outside temperature and will allow it to run efficiently with reasonable cycling even if the boiler is oversized. Is this a valid way to look at modulation and efficiency? I don't want the boiler cycling and blowing hot air at me and going on and off too frequently. There have been times when the Weil McLain Ultra 230 has not been able to keep up with the heat demand on very cold windy days.
The hydronic system goes into four air handlers two in the unfinished basement and two in the unheated attic.
The home is 4,300 square feet two story with a basement. It has a very significant number of windows to the rear of the home which faces Northeast. The great room facing north has an eighteen foot ceiling.
The home is in southeastern Massachusetts within four miles of the coast (lots of heavy wind). Glass is Pella Proline double pane and insulation is normal for a ten year old custom home. Attic is R-38.
I am thinking of adding radiant heat to the master bathroom.
My wife hates to be cold. Happy wife Happy life.
I would greatly appreciate any insights and knowledge to help me make a decision. Thanks again.