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Crown Boiler Piping Question

I have been in my house for approximately 3 years. I noticed issues with the Crown, Series 32, boiler but didn't know the extent of the problems until 2 years in. I don't know how old the Crown boiler that was replaced was and incorrectly thought that it would be original for the house. Upon closer inspection I found multiple holes in the tops of the cast boiler sections leaking water and steam. It was time to replace the unit. I contacted a couple of local companies that specialized in steam heat but none wanted to take on the project. One suggestion was to simply replace the Crown boiler sections with new sections. With a call to Crown/Velocity, which had the sections in stock, I decided to replace the 6 sections myself.

After install, and a second replacement of a bad cast section, the system was up and running last season. My hope was that the original system of piping would work correctly if only the boiler was replaced with an identical system. I dealt with the surge and skimming last season but found that, when the temperatures were cold enough to have the boiler cycling quickly, the water would disappear in the sight glass. I am assuming there is a vacuum situation somewhere in the system. And that the holes in the old boiler masked the problems?

One concern I have relates to the 3 inch header pipe required in the Crown install manual. After installing the boiler, I started to question the header piping that was already part of the system. The header starts at 3 inches, is reduced to 2 inches and then increased to 4 inches. Pictures attached. I have read a number of books on steam heat and have seen some issues about the water disappearing in the sight glass being addressed in the blog.

Are there any thoughts on the 3" down to 2" and back up to 4" on the header piping that may be a problem?


    EBEBRATT-Ed Member Posts: 15,534
    Unfortunately your piping is well.....a mess!!

    Download the manual for your boiler and follow the piping drawing.

    It will never work right as is and may lead to premature boiler failure.

    The two boiler risers need to be tied together then feed the system and then the equalizer in that sequence. And the piping needs to be the right size, yours is way too small. If you capped the left side of your existing header, tied the two risers together at the inlet of your old header that would be the right sequence. Risers are too small and can't see equalizer or return piping Hartford loop.

    Long story short...total repipe

    Check "find a contractor" on this site and post where you are located if you need help
  • mattmia2
    mattmia2 Member Posts: 9,660
    Calculate the edr of all your emitters as well and figure out if that boiler is even the right size.
  • nicholas bonham-carter
    nicholas bonham-carter Member Posts: 8,576
    The piping is certainly not ideal, but if you can keep your pressure down to a few ounces, with a vaporstat, 15 ounce gauge, and generous main venting, you may be able to limp through this winter, until repiping in the spring.
    For every ounce of steam pressure, the water level in the return piping rises 1.75 inches. Over pressure can suddenly empty a boiler, especially, if there are horizontal pipes in the return piping, (at a greater height than the required boiler water line).
    Definitely calculate your radiators EDR, to verify that the boiler is not too big.—NBC
    Alan (California Radiant) Forbes
  • Patterson
    Patterson Member Posts: 2
    Thank for the follow up and information. There is no issue keeping the pressure down and I am anticipating being able to limp through the winter. I am in Pittsburgh PA and cannot find a local contractor from the "find a contractor" on this site. When I try to find a contractor, the closest option is hours away.
  • Ironman
    Ironman Member Posts: 7,376

    Bob Boan
    You can choose to do what you want, but you cannot choose the consequences.