In hot water


  • I know several people who live in fairly new houses that have the "ultra-efficient condensing boiler" system you speak of, and I have yet to hear the end of it - about how awesome it apparently is etc. - but with that said, holy cow I didn't know it was that expensive!

    I guess maybe if the rebates totaled 4k (they likely won't, typically they are 2k max) and it brought the overall cost to 6k it wouldn't be as hard to stomach as 10k, but either way it's a large investment.

    Really hope you guys figure out away to pull it off!
  • fyi i had my previous post broken down into readable paragraphs, however you won't see them if you are viewing the comments on the post and not through the discussion thread :)
  • Here's the problem you're facing, speaking as someone in the exact same boat: you can't get efficient without redoing everything. And I do mean everything. Which includes the hot water heater. And that doesn't mean upgrade - that means replace with an indirect fired unit. The other problem is that the boiler you have looks like it was probably self-installed meaning it may not be sized correctly. In fact, chances are very high that the boiler is not sized correctly. Which means new measurements need to be taken and new BTU calorics need to be calculated.

    Having spoken with over a half dozen contractors, the wall mount units? Are generally not suitable for a home of that size unless designed for cascading operation. Especially not with old style radiators, which are highly inefficient. Most of the "efficient" units are also rated at hot water temperature (160F) whereas the correct water temperature for baseboard / radiant is 190F. Because the base system is so old, an aluminum heat exchanger has a higher likelihood of the copper/aluminum reaction problems occurring unless you watch the loop water like a hawk.

    That said, your realistic options are actually not as bad as you might think. Option A would be to use a slightly less efficient boiler with a cast iron heat exchanger. This drops your boiler costs significantly by replacing like for like, essentially. You still get better efficiency (84%+ for Weil-McLain who is highly recommended; my Weil-McLain is 30 years old and has the original thermocouple,) the boiler will cost less - often by several thousand dollars - and you'll only need to replace the missing copper lines with new copper lines. Other manufacturers that come highly recommended from professionals and have high efficiency cast iron are Utica and Columbia Boilers. I can speak to Weil-McLain's longevity though - mine was installed in 1982 and has only had three problems ever, all minor, excepting the circulator.
    Option B would be to go for a highly efficient condensing boiler system with an aluminum heat exchanger, which given the age and size of the house, will most likely pay for itself over time. The problem with B is that you will need to replace all of the basement lines with high temp PVC and/or stainless (minimum last three feet,) the boilers are much more expensive (typically over $7,500,) and to realize efficiencies you'll need to replace the hot water heater with an indirect fired system. There's also increased maintenance due to the system containing aged copper and cast iron - pH levels of the heating loop must be monitored very regularly to avoid destroying the heat exchanger.
    Option C would be Full Replace. For maximum efficiency this is definitely the route to go. Especially since you already need to replace some radiators. Here's the problem with Full Replace - HOLY CRAP EXPENSIVE. It allows you to resize and rezone the entire house for the maximum possible efficiency across the board, meaning you can realize >91%. But it means replacing the radiators with baseboards most likely - standing radiators are very hard to find in the US and very expensive. Burnham Hydronics makes some standing radiators, but they generally cost upwards of $1,000 each.

    All that said, let's talk radiators for a moment. Radiators, are radiators. They're made of metal. They either leak or they don't - the rest is external, cheap, and replaceable. A properly cleaned used radiator will perform just like a new radiator. If you want to keep the look, I'd start hitting up the neighborhood for people replacing their systems. If the radiator passes a pressure test, clean it out, put a fresh coat of paint on it, and call it a day.

    $10K is also unreasonably low, I'm sad to say - I'm seeing quotes in the $10-12K range for a house with half the work involved (new boiler, no wire pulls, only replacing last 3 feet of plumbing) and half the space. Because it's an old radiant system, I honestly would recommend getting more opinions, especially from licensed hydronics experts - not the same as plumbing or HVAC, though usually a subset of HVAC. I also would strongly recommend a hydronics expert to evaluate the entire house, which means taking measurements of everything to ensure the system is sized properly. An undersized or oversized system will be extremely inefficient no matter what boiler you use.
  • RootWrym, I completely hear what you are saying, this is always a difficult decision making process, deciding what would be the best/reasonably priced method to go with.Be assured Soley Heating & Cooling are one of the most professional companies I have had the pleasure to work with. The are not just HVAC, they have over 60 years experience and have dealt with every form of heating system available and some that are even obsolete these days. They also are licensed hydronics experts which is the main reason I introduced them to Lincoln and Brian. I'm positive they will find the best solution for the project without making them spend money that would be unnecessary for the guys.
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