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oldhomeowner_2007

HELP me choose a natural gas chimney vented boiler

I have baseboard heating and need to replace my 1983 Weil McClain boiler. It is currently an input of 140K BTUs and output of 110K BTUs. One plumber came to give me an estimate. He only measured the baseboards and supposedly just factored in a 10% heat loss with no assessment of the house. He recommended a Peerless mi-04 unit with 105K BTUs. I want a unit that is built to last that has a good history of minimal problems (does that exist?). And how do I know I am picking the right size without doing a heat loss assessment. Is there a way to just guess? I live in an old 1910 home that has been renovated in the 80s.
Can I get opinions on Peerless owners or plumbers?
I welcome any thoughts on Crown, Burnham and other other brands that use gas and are chimney vented. I am not interested in direct vent or too high efficiency since I do not believe my chimney is lined. Please provide model numbers if possible. I am having a hard time picking within the same brand line. What makes one better than another other than efficiency? Thanks in advance!!

Comments (3)

  • jackfre
    9 years ago

    Your plumber giving you the load based upon the amount of radiation is actually ok. You will get X amount of btu/ft of radiation. If that has been heating the house then ok. In fact, if the house has been warm then the boiler may as well be sized to the amount of radiation. Anything more is excess capacity.

    I had a Buderus G224 with their outdoor reset program, which you want, for 12 years and it was excellent. I'd take a Buderus over the others.

    Undrstand that your chimney is an issue. You say it is not lined. In order to use a "chimney" unit you will have to put an appropriate sized liner installed in your masonry chimney. The staight masonry chimney will not meet the code. You don't want a direct vent or a higher efficiency unit and I understand your reasoning, BUT. Consider the cost of the liner for your current chimney to bring it up to code. Add that to the boiler install cost and I think you will be in the price range of a wall hung condensing modulating boiler. The efficiency of which will be 95-96% vs your proposed 80-82%.

    BTW the outdoor reset system will vary the output temp of the boiler as the outdoor temp changes. You do not need the same output temp on a 45* day as you need at a 10* day.

    If your contractor says your current chimney is ok, he is wrong.

  • oldhomeowner_2007
    Original Author
    9 years ago

    Thanks for your response! I appreciate the advice.

  • DreamingoftheUP
    9 years ago

    Are you sure your boiler "needs" to be replaced? I've got a WM boiler that was installed, per the records from the previous owner, in 1970. The only things I've had to replace over the years have been the pumps, a thermocouple and one of the low voltage transformers/relays. The pumps were my fault since I wasn't diligent in oiling them (B&G Series 100). Since I did all the replacement myself, the cost was parts only. There's nothing wrong with the boiler itself, outside of being inefficient. Of course, if yours is leaking between the sections or has a crack.

    A couple years back I started the search for a super-duper efficient replacement. What scared me off were two things: the high price and the online horror stories of failed computer boards & blowers, frozen exhaust lines, etc. So far, I've decided to keep what I've got and let the next owner worry about replacing it.