Plumber or Boiler Tech?

Discussion in 'Water Heater Forum, Tanks' started by mcouture87, Oct 20, 2020.

  1. mcouture87

    mcouture87 New Member

    Joined:
    Oct 20, 2020
    Location:
    Maine
    I have a 20 year old boiler with tankless hot water. Hot Water Performance always was bad. I'm thinking of getting a hybrid water heater and bypassing the boiler altogether.

    Who should I bring in to revise the plumbing to the boiler and new water heater? Plumber or boiler tech?

    Is it a matter of just not feeding the coils in the boiler or is there any wiring on the boiler to prevent 'something'?

    The boiler will still be used for baseboard heat in the short term but I'm looking at doing some mini-split heat pumps to either supplement or replace the boiler altogether....

    Here's what I got:

    boiler.JPEG
     
  2. Dana

    Dana In the trades

    Joined:
    Jan 14, 2009
    Location:
    01609
    Just about any competent plumber in Maine would be able to correctly install the hybrid water heater and cap off the tankless coil in the boiler. The boiler will continue to work just fine with the domestic hot water disconnected from the tankless coil. The controls for the coil are pretty dumb, amounting to setting the minimum idling temperture.

    But a boiler tech would be the person to advise on how to adjust (or even replace) the controls on the boiler for higher efficiency. A heat purging economizer control can save quite a bit on oil use by reducing the average boiler temp, which can now be much lower if it's not serving up hot water. That part not really plumbing job.


    A hot boiler in a poorly insulated basement boiler room means a large amount of the idling loss heat is truly lost. In order to serve up hot water at any reasonable rate the idling temp of the boiler has to be fairly high, which results in much higher jacket losses to the boiler room, which doesn't appear to have any insulation on the foundation walls(?), and no interior vapor or air barriers on the framed exterior wall (?). But even with a cold-start boiler and no tankless coil those losses are pretty high, easily accounting for a double-digit percentage of your overall oil uses, even when not actively heating the basement.


    When re-plumbing the near-boiler if the pipes can be moved to provide sufficient clearance to install 2.5" of foil-faced rigid polyiso (R15) on the foundation wall (R15 continuous insulation is current IRC code minimum in your climate zone) those losses can be reduced dramatically. To be fire-safe there needs to be a thermal barrier against ignition (half inch wallboard glued to the foam works, or mounting on strapping through-screwed to the foundation with masonry screws), and the area around the flue pipe would need to be R15 rock wool (and NOT fiberglass or foam). Check local codes on how much clearance from combustibles when insulating around flues. Some local codes would allow contact with rock wool (which has a melting temp higher than steel), others would still require some air clearance from the pipe.

    The pink fiberglass open to the boiler room air without an air barrier or vapor retarder creates high wintertime moisture levels in the exterior sheathing of the framed wall portion. At the very least the fiberglass needs to be re-installed for snug fit (for R-performance) with no compressions or voids, covered with air tight latex painted wallboard (about 3-5 perms) but it probably needs "vapor barrier latex" primer (about 0.5 perms) , or 4-6 mil polyethylene (0.05-0.1 perms) or a "smart" variable permeance vapor retarder to reduce moisture risk. The approach that makes the most sense depends on the material stackup of the sheathing, weather barrier & siding, and your budget. But what you have now is fairly high risk for developing mold conditions on part (or all) of the exterior sheathing.
     
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  4. Sylvan

    Sylvan Still learning

    Joined:
    Sep 23, 2004
    Occupation:
    plumbing - fire suppression - boiler inspector
    Location:
    New York
    As a "plumber" we install and even service gas fired boilers, we do low pressure boilers inspections and let me tell you I would have failed the installation you posted


    SLOPPY workmanship BUT considering it is an oil fired boiler a plumber should not touch the oil piping as most of the time their license does not cover "oil" that would be an class A (oil) boiler installers license

    The tempering (mixing) valve was installed wrong

    I am sure the installer tried but could not find a cheaper one to install

    Amazing how the installer "Knew" the outlet temperature of the tempered water without any gauge on the outlet .

    They must know by feeling the piping as they did the adjustments UNLESS they wore gloves

    The wiring looks like it must have taking at least 15 minutes to install it

    I wonder if the piping installer knows insulation is a lot cheaper then the heat loss this system is losing and this of course is a violation of the energy code in a civilized area
     
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  5. Dana

    Dana In the trades

    Joined:
    Jan 14, 2009
    Location:
    01609
    You realize this is Maine, right? :)

    Past sins of the existing installation notwithstanding I'd still hope a competent installer for a shiny new heat pump water heater would at least get the new tempering valve, T & P valve and condensate disposal stuff up to current code, even if code enforcement is pretty lax (or nonexistent) in much of rural Maine.

    The wall insulation isn't up to current code either, but that's mostly DIY-able. Check the boiler manufacturer's installation manual (is that a Burnham?) for side and back clearances to combustibles when making a wall insulation plan.
     
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  6. fitter30

    fitter30 Well-Known Member

    Joined:
    Feb 2, 2020
    Occupation:
    Retired service tech
    Location:
    Peace valley missouri
    Have never seen that sheet metal setup feeding combustion air to the burner any info about it. Wonder when the dhw coil was cleaned and what water temp the boiler runs at?
     
  7. Dana

    Dana In the trades

    Joined:
    Jan 14, 2009
    Location:
    01609
    That isn't uncommon in the cooler northeastern states, where they cobble together some ductwork with an AC zone damper to open & close the combustion air intake. It's often coupled together with automated flue dampers with interlocks to "prove" both the flue and combustion air paths are open before allowing the burner to fire.
     
  8. AvaLambert

    AvaLambert New Member

    Joined:
    Mar 14, 2021
    Location:
    New York
    As a plumber, I can recommend you to replace it, due to the fact that even if you have been trying to repair it, it would be broken in 2-3 months again. I have pretty big experience with such boilers, and it doesn't depend on plumber's repair skills. To install a new system is really easier and cheaper than try to revive this boiler. It can make even beginner one. Reminding my first year after finishing courses which I have found on howtobecomeaplumber.org, I could implement and more complicated projects. Hope that now at you everything is okay :)
     
    Last edited: Mar 21, 2021
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