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Steam Boiler: Does the installation of a "Hartford loop" matter?

A new Dunkirk model 400 was recently installed and has yet to function properly, the boiler overfills.  In conversation with the installer, a Mr. John Groya of Bay City, MI, I suggested that a "Hartford loop" might help.  That suggestion was immediately discounted.  My suggestion was that it would help to reduce the "apparent" draw down of water by effectively increasing the reservoir volume, subsequently reducing the amount of fresh water that would have to be added per cycle.  Does the installation of a "Hartford loop" matter? 

While I'm asking, does anyone know if Michigan boiler codes require the installation of a "Hartford loop?

Lastly, due to the frustration of having a new furnace that requires daily attention I've read up on the unit and have found that the LWCO is installed such that the fill line intersects the center of the glass watch tube, this contradicts the manufacturers instructions and according it sounds most likely to be responsible for the unit overfilling.  Should the LWCO be reinstalled in a lower position to correct the problem or would a "Hartford loop" take care of it? 


  • BobC
    BobC Member Posts: 5,227
    Follow the manual

    With very few exceptions a hartford loop is required by the boiler manufacturer, inspectors, and insurance companies. It is for protection against a broken return pipe that might allow a boiler to drain in the ec=vent of a leak in the return.

    A boiler must be installed in compliance with the installation manual, if it is not your boilers warranty will be null and void and your house insurance could also be null and void. The manual is very clear on where the LWCO should be installed, failure to install it correctly could result in excess water being fed into the boiler; that will dramatically shorten the boilers lifespan.

    Tell your installer that if does not want to follow the manufacturers manual you will ask that the boiler installation be inspected by a representative of the boiler manufacturer. DO NOT pay him any more money until it is installed correctly.

    Post some pictures of the boiler and the piping around it so we can see what else he may have done improperly.

    Smith G8-3 with EZ Gas @ 90,000 BTU, Single pipe steam
    Vaporstat with a 12oz cut-out and 4oz cut-in
    3PSI gauge
  • Eric_32
    Eric_32 Member Posts: 267
    I've only installed,

    I've only installed a few different brands of steamers, but on all of them, the boiler came equipped with the low water cutoff installed already from the factory.

    It was not something I did.

    What are you using for an auto feed?
  • Overfilling in Michigan

    Definitely the boiler installation instructions must be followed in the placement of the LWCO, presence of the Hartford loop, and pipe size and placement.

    I don't think the faults you mention are the cause of the over-filling. More likely over-pressure while steaming is pushing the water out of the boiler up into the returns (which perhaps are clogged). Alternatively, if the water is very dirty, it may be racing up the supply pipes with the steam.

    Cut off the water supply to any auto/over-filler, and watch the water-level as the boiler steams. When the water disappears, time how long it takes to come back. Verify that the LWCO will actually cut off the burner as the water drops.

    Remember that we are talking about a boiler, instead of a furnace here for the sake of clarity.--NBC
  • JohnNY
    JohnNY Member Posts: 2,738
    There are two problems with this thread.

    1. The original poster didn't need to post the installer's name, and that said,...

    2. An installer who omits the Hartford Loop is likely to have very little idea what else to do right with a steam boiler.
    Contact John "JohnNY" Cataneo, Master Plumber
    in New York
    in New Jersey
    for Consulting Work
    or take his class.
This discussion has been closed.