How to Check a Boiler for Freezing Cracks?

Discussion in 'HVAC Heating & Cooling' started by molo, Sep 10, 2009.

  1. molo

    molo Member

    Messages:
    849
    Location:
    cold new york
    There has been some freezing damage to some of the components of the boiler (outside of the boiler). I want to check the boiler itself and am not sure how to simulate the pressure it will be under during normal operation. I would like to hear what you guys think I could do here.

    Thanks!
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,273
    Location:
    New England
    You could attach fittings to the outputs, and put a schrader valve in one of them, you could pressurize it with an air pump. 20-25# should be safe...just keep it below the (probably 40#) of the overpressure relief valve. Keep in mind temperature changes will change the air pressure, but it should hold overnight. You might hear air escaping if it's bad or never be able to build up pressure. If you could get some water in there before you pressurized it, the wetness may be easier to see. Some cracks may not open until things are heated up, which would be much harder to find just sitting there.
  3. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,062
    Location:
    Cave Creek, Arizona
    damage

    Seal, or shutoff, all the boiler connections and then connect a hose to the drain valve and fill the boiler to 20 psi.
  4. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Are residential boilers and any work done on them, subject to inspection by a state boiler inspector?

    My brother in MD is in a model steam train club, and they must have their engines inspected annually and after any major work.
  5. molo

    molo Member

    Messages:
    849
    Location:
    cold new york

    This is a good point. There are no inspections required in this area. One of the concerns with this boiler is that because there was freeze damage and water leakage on the outside (we haven't checked the inside yet) there has been waer damage to electrical components as well as water fittings. We're trying to decide if it's a replace or a repair.
  6. Furd

    Furd Engineer

    Messages:
    446
    Location:
    Wet side of Washington State
    It depends upon several factors including the BTU/hr. input rating, the maximum pressure and/or temperature and the "occupancy rating" as determined by the building code along with (as always) the local code interpretations.

    However generally, boilers in residences of less than 6 families are exempt from inspection.
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