Viessmann or Weil McLain Boiler for 4-zone radiator/radiant/baseboard domestic system

jimbo48

I am a homeowner in northern New England looking to replace a 1985 Weil McLain natural gas-fired boiler probably nearing the end of its life cycle. The wood-frame colonial-style house I am heating was mainly built in the 1930's and is about 3200 S.F. and the present system has four zones: one with cast iron radiators, heating about 1400 S.F.; one with radiant heat (copper in concrete slab, 6 loops), heating about 800 S.F.; and two with baseboard, heating two additions added in the 1990's, each having about 500 S.F. I have gotten two very different proposals from reputable heating installers, both saying the existing Weil McLain, which is rated at 247K BTU's is too large, and both saying the right size should be about 125K to 130K BTU's. One is recommending a Weil McLain GV90+5, with separate domestic hot water tank off the boiler, at an installation cost of about $; the other is recommending a Viessmann Vitodens 100-W B1HA, 35kw, also with separate domestic hot water tank off the boiler, at an installation cost of about $. Each is saying that their recommendation is the best, but the one recommending the Weil Mclain is saying the wall hung Viessman recommended by the other is definitely not the right boiler for the job. I do not know where to turn--are both systems Ok? Is one a better application than the other? is either one (or both) NOT a good application? I would greatly appreciate anyone's help.

Steve Minnich

We don’t discuss pricing. It’s a rule here.

I couldn’t tell you a good reason to not choose the Viessmann as long as your contractor has access to replacement parts if needed.

They’re a rock solid company that stands by their product. If it were my home, my choice would be the Viessmann CU3A. It's a floor model with a high water content and little chance of short cycling.

jimbo48

Thank you, Steve. I appreciate your insight and advice, and I sincerely apologize for the mention of pricing. I wasn't aware of the rule, and if there's a way to edit the post to delete the reference to pricing, I would gladly do it.

Erin Holohan Haskell

Thanks, @Steve Minnich.

@jimbo48, I've pulled the pricing from your post. For the future, here's how you can edit your posts, along with some other tips for using the forum: https://heatinghelp.com/forum-user-manual

jimbo48

Thank you, Erin, and, again, please accept my sincerest apologies.

Erin Holohan Haskell

jimbo48 said:

Thank you, Erin, and, again, please accept my sincerest apologies.

Thanks, @jimbo48. Welcome to Heating Help!