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high efficiency gas boiler - brand advice

Jris
Jris Member Posts: 3
edited June 2020 in Gas Heating
Folks, I'm in the midst of purchasing my first home (1.5 stories, unfinished basement, approx. 1300 sq ft) in Boston. One of the upgrades I'm executing is a new high efficiency gas boiler & indirect water heater; the current boiler is a 30+ year old Burnham (water heater has a few years left, but when in Rome...). I'm tying to gather data on reliable brands for a >= 95% efficiency unit. I've had one plumber recommend Burnham (again), another Lochinvar, and - unfortunately - I'm out of my depth here. Any advice on what brands to focus on or avoid? This being Boston, I'm comfortable paying for quality.

Comments

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 10,374
    You will get many different answers. The best decision is usually the best installer using a boiler he likes. The best boiler installed by a slob is a poor choice.

    Viessmann is usually considered the Cadilliac
    Lochinvar
    HTP
    The list goes on
    Ironman
  • Jamie Hall
    Jamie Hall Member Posts: 17,170
    Installer first. Then worry about the boiler. If the installer is good, the boiler will be. If the installer is so-so or bad, it doesn't matter what the boiler is -- the result will be ... unfortunate.
    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Ironman
  • Steamhead
    Steamhead Member Posts: 14,863
    What model Burnham is in there now?
    All Steamed Up, Inc.
    Steam, Vapor & Hot-Water Heating Specialists
    Oil & Gas Burner Service
    Consulting
  • Jris
    Jris Member Posts: 3
    Thanks, all. I'll grab the Burnham model that's in there now later this week (next time in house - stupidly blurred the photo I took at first, but it had a 1988 install date...)
  • Zman
    Zman Member Posts: 7,009
    When you look carefully at the residential condensing boilers on the market today, you notice that at least 90% of them are using the same 2 stainless steel heat exchanger designs. Models like the Lochinvar KHB series utilize a "water tube" design which has a proven track record of over 30 years. The Lochinvar WHB series utilizes a "fire tube" design which has been on the market for at least 15 years with great results as well.

    As for the other < 10%, proceed with caution. Some of the "tube in tank" models from HTP perform quite well, Aluminum heat exchangers can be problematic.

    When you look at the brochures for most models available, you will notice that most are either firetube or watertube. In fact, many of the manufactures source their heat exchangers come from the same factory.

    When you are looking for recommendations, don't get too hung up on the brand. A correctly sized boiler which is installed per manufactures instruction is the most important part. The contractor should be performing a heat loss calc to size the boiler, they should install per instructions and tune the boiler with a combustion analyzer.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    Ironman
  • Jris
    Jris Member Posts: 3
    Yeah, I noticed the Lochinvar recall - definitely a red flag, and others have hinted at some difficulties with the brand before.
    Zman
  • Zman
    Zman Member Posts: 7,009
    edited June 2020
    @SweatHog @Jris
    I am going to have to go ahead and uh... disagree with you on that.
    All condensing boilers occasionally have issues with harmonics from combustion and sometimes gas piping. It usually can be eliminated when the instructions are followed and combustion analysis is performed.
    As for the recall, we are talking about 7 cases out if approx 40,000 units. I respect Lochinvar for erring on the side of safety. It should be a pretty simple fix.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    CanuckerGroundUprick in Alaska
  • flat_twin
    flat_twin Member Posts: 292
    edited June 2020
    Highest efficiency comes when the boiler water returns to the boiler at less than 140 degrees and lower is better. A survey of your emitters, baseboard fin or cast iron rads should be done to determine if this is possible. Sometimes the simpler, less expensive, slightly less efficient boiler is the better choice.
  • SweatHog
    SweatHog Member Posts: 7
    @Zman. Yes, boilers occasionally have issues with combustion. But in Lochnivar's case the problem was compounded by the absence of combustion adjustment directions in the service manual discovered by @OaklandNS where he said the Lochinvar manual: "provided no provision for adjusting low-fire combustion. It appears that the service manual has since been updated on Lochinvar's website to recommend adjusting the offset on the gas valve by very minor amounts to dial in low-fire combustion." Lochinvar's have nice features. However, they update their product lines so often it's become and invitation to quality control issues.
  • Zman
    Zman Member Posts: 7,009
    @SweatHog
    We can agree to disagree on this one.

    I like that Lochinvar is constantly improving their products. The modulating control over the boiler circ for example has been a long time coming. Personally, I find the controls very intuitive.

    You seem to be basing your judgment, at least in part on a homeowner's post where they are confused about how to adjust the offset on one of the most common gas valves on the market.
    To me, it makes sense to discourage homeowners and most techs from playing with the offset screw. Improper adjustment can make a hot mess of things.
    "If you can't explain it simply, you don't understand it well enough"
    Albert Einstein
    rick in Alaska
  • mazz
    mazz Member Posts: 34
    Thanks so much for all of your comments & advice ,my wife & I are currently having inspections on a 23 year old log home we plan to purchase that has 2 Weil-McLane boilers w/ 1 indirect tank , each boiler is 175,000 BTU’s ...cast iron with stainless steel venting & only 80-82 % efficiency. They are both located on 2nd floor & used to heat a radiant PEX tubing 4,200 sq ft bottom slab concrete floor with 4-5 zones.....we had a bid of approximately 20,000 $ to replace both with Lochinvar boilers & new pumps ECM ‘s , which the contractor said would save about 250-500 per month in energy cost. Both original Weil-McLain’s are LP . Would appreciate any advice on this .
    Thx Mazz
  • hot_rod
    hot_rod Member Posts: 15,066
    I'd sure get that $250-500 per month savings in writing :)
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Ironman
    Ironman Member Posts: 6,603
    mazz said:

    Thanks so much for all of your comments & advice ,my wife & I are currently having inspections on a 23 year old log home we plan to purchase that has 2 Weil-McLane boilers w/ 1 indirect tank , each boiler is 175,000 BTU’s ...cast iron with stainless steel venting & only 80-82 % efficiency. They are both located on 2nd floor & used to heat a radiant PEX tubing 4,200 sq ft bottom slab concrete floor with 4-5 zones.....we had a bid of approximately 20,000 $ to replace both with Lochinvar boilers & new pumps ECM ‘s , which the contractor said would save about 250-500 per month in energy cost. Both original Weil-McLain’s are LP . Would appreciate any advice on this .

    Thx Mazz

    What's your locale?

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.
  • mazz
    mazz Member Posts: 34