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Advice Needed

tomklein11 Member Posts: 4
edited March 2019 in Gas Heating
Hello and thanks in advance for some advice,

We live in Wisconsin and are looking to update our 25 year old Weil-McLain gas boiler. We expressed interest in a high-efficiency model and were quoted to replace our current unit with a ECO 155MBH SERIES 2 150,000 BTU 95% efficient Boiler.

Our home is a 2,400 square foot ranch with hot water radiant heat and one control thermostat.

We know NOTHING about this type of stuff so forgive our ignorance on the questions.

1. Does it make sense to go the high-efficiency route for our home in Wisconsin?
2. Is this the best WM high-efficiency unit for our home?
3. Are there any considerations we should make with regard to replacing our existing hot water heater because of this potential new system?

Any other help or thoughts are appreciated.


  • Intplm.
    Intplm. Member Posts: 1,376
    Careful! We do not discuss pricing here.
    The best thing for your house is to have a good/reputable service company give their recommendations. That company should do a heat loss calculation of your home and work from that, sizing the boiler and radiation to the heating needs of the home.
    Weil McClain is a very good boiler manufacturer. I have worked with many.
    As to the water heater replacement. Same thing. Sized to your plumbing/domestic hot water use of the home.
    Get some quotes from a few companies. see what they say. Hopefully whoever you choose will have a good and long lasting relationship with you and the new boiler.
    Erin Holohan Haskell
  • Jamie Hall
    Jamie Hall Member Posts: 18,962
    Kindly remove the price figure in your post -- we never talk price on this site, as it varies so much with region and other factors.


    That said, it may or may not make sense to install a mod/con boiler. They work well, but they are just one part of the system which has to be considered as a whole, not piece by piece. The first thing to do, then is to find out the heat loss of your house. Slant/Fin, among others, makes a handy heat loss calculator (https://www.slantfin.com/slantfin-heat-loss-calculator/) which will take some time to use, but is worth the effort. Make note of both the room by room figures and the total. Then look at the radiation in each room, and compare it with the heat loss from that room. What temperature are you going to have to run that radiation at to stay warm? That's critical, since mod/con boilers gain their higher efficiency by being able to run the radiation at a lower temperature. That same calculator can provide some assistance in that regard, too.

    The overall heat loss of the house will guide you to the right size boiler. You want to match the heat loss; bigger is not better in heating.

    On the water heater -- how do you heat your domestic hot water now? Very often the best approach if you need to replace the water heater as well is to use an indirect tank heated from the heating boiler. Otherwise a separate gas fired tank type water heater might be the way to go.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Erin Holohan Haskell
  • pecmsg
    pecmsg Member Posts: 2,898
    The installing contractor is the most important aspect of the purchase. Have they been trained, have spare parts available when needed, are there for the long term?
    JUGHNE Member Posts: 9,765
    Do you have baseboard heaters? Is your house the age of the existing boiler?
    That 150,000 sounds big for your house.
    If you do the heat loss yourself and without showing your data to a contractor, you could see what he comes up with.
    What size is your existing boiler?
  • tomklein11
    tomklein11 Member Posts: 4
    Thanks to everyone for advice thus far.

    The home is currently heated by baseboard heating and the system is a Weil-McLain HE-6 (DOE rating 137,000 Btu/hr capacity)
  • Zman
    Zman Member Posts: 7,330
    Do a heat loss calc on your house. A 150 is likely twice what you need. That is a bad thing, it will will reduce efficiency and longevity.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein