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Choosing a new boiler

choosinganewbolier Member Posts: 1
edited February 22 in THE MAIN WALL
Hello -
I have been getting quotes for a high efficiency boiler to replace my 30 year old boiler that is original to my 1991 Center Hall Colonial, which we have owned for 8 years in northeastern Massachusetts.
The house is 3900 sq ft.
3 Heating Zones
Forced Hot Water Fin base board heaters with about 100' of baseboard on 2 zones and a lesser amount on the 3rd zone.
I have an Amtrol 40 gallon Indirect that I believe is original to the house. Works fine - not planning on replacing this at this time.

Each HVAC contractor has recommended a 150 - 155BTU unit, which I believe they've matched with the current boiler.

My main question - how do you choose between the brand they are offering?

Option 1: Triangle Tube Instinct 155
Option 2: Lochinvar KHB155
Option 3: Lochivar NKB199N
Option 4: Burnham Alpine 150
Option 5: Bosch Greenstar 151

Please help, educate me.
Thank you.


  • Jamie Hall
    Jamie Hall Member Posts: 15,350
    All four of your options are very good boilers. All four will perform very well, if they have been properly sized (did any of the folks do a heat loss calculation on the house? If not, you can forget them right away) and properly installed.

    None of them will work well if they aren't properly sized and installed.

    So -- the real answer to your question isn't what make of boiler, it's which contractor seems to be the most capable of doing the job right. Did they do a heat loss calculation? Did they look over the rest of the system? Is their organization capable of standing behind and servicing the product they sell (all four of those take a fair amount of maintenance -- and a lot of understanding to set up correctly)?
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.
    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
    JUGHNE Member Posts: 8,151
    What is the total length of baseboard heaters in the house?
    We assume 3/4" copper tube?
    And on the coldest day are you warm enough?
    EBEBRATT-Ed Member Posts: 8,519

    I would be careful. All those boilers seem over sized to me . I am sure none of them have done a heat loss. They never do
  • There was one heat loss assessment done - he calculated, if I recall about 260' of 3/4" base board, measured all rooms, windows, and exterior doors. If I recall he came up with a 157k btu assessment.

    Yes on the 3 zones we are very comfortable in most all rooms with the current set up.

    Thanks for your responses and the time/effort to respond. Your help is appreciated.
    JUGHNE Member Posts: 8,151
    The reason for the BB length question is that I have a boiler change out to do.
    1966 double wide house with boiler and BB....very unusual for this area.
    Doing a heat loss on that with a lot of unknown R values is sketchy.

    Then I realized he had only 97' of 3/4" BB.
    IF it put out 600 BTU per foot he was only getting 58,200 BTU into the house and he was comfortable.

    That output would not be 600 per foot, and dependent on water temp....180 in his case.
    But it kept me from overshooting boiler size "to just be sure".

    So in your case with the 260' X 550BTU (someone please correct me if needed), the most you can put into the house is 143,000 with the BB delivery system you have.

    This is not the way to size a boiler, but as you see in my case above, prevents one from oversizing.

    Also you may not reach the touted high efficiency rating of the high efficiency ModCon boiler.
    They acquire that 95% or more number by having relatively cool water returning to the boiler.
    BB heaters may not be able to do that.

    I have one in my house, but mostly have radiant heat that achieves that cool return.
    The little job I mentioned above will get an "old school" cast iron boiler.
    He still has the original 1966 working, but just wants to avoid total failure as parts are becoming scarce for his.....and he has a usable chimney...often a reason I put in the ModCon with the PVC venting.
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