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Riser Leak Noticed-Any guesses as to what we'll find?

cubicacrescubicacres Member Posts: 302
After firing up the boiler a few weeks ago for the season, we just noticed some water on the basement floor and saw it was coming from the last riser to the 1st & 2nd floor tennant bedroom radiators as shown in the photos (then one more 1st floor hall radiator/riser after that, then it returns via the ceiling dry return back to the boiler room & drops to the boiler). We'll take off the insulation and look up the riser to see if we can isolate the leak area (and go into both bedrooms to see if it's near the radiator valves or the pipe run itself that's leaking-with any luck this might be a big portion of the higher water use we noticed the past season). Any thoughts on what it might be/stopping the leak & letting the insulation dry out & replacing it in a few days/weeks, or does fiberglass insulation lose effectiveness long-term after being wet for a while & should be replaced with new insulation?


  • ChrisJChrisJ Member Posts: 11,256
    Wet fiberglass
    Single pipe quasi-vapor system. Typical operating pressure 0.14 - 0.43 oz. EcoSteam ES-20 Advanced Control for Residential Steam boilers. Rectorseal Steamaster water treatment
  • Jamie HallJamie Hall Member Posts: 13,412
    Fiberglass insulation can be dried out... eventually... but if it's been at all compressed while wet, it never really recovers. Better to bite the bullet and replace it. As for finding the leak... assuming that this is meant to be a dry return (not standing water like a wet return), the most likely places are the threads of fittings. Particularly any where the pipe turns from vertical to horizontal, or vice versa. Always assuming that you don't get lucky and find a leaking valve...
    Br. Jamie, osb

    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England.

    Hoffman Equipped System (all original except boiler), Weil-Mclain 580, 2.75 gph Carlin, Vapourstat 0.5 -- 6.0 ounces per square inch
  • Larry WeingartenLarry Weingarten Member Posts: 1,912
    Hi, When looking for the leak, I'd start at the highest possible point and work your way down. It MIGHT be less work that way. :p

    Yours, Larry
  • JUGHNEJUGHNE Member Posts: 7,195
    When I could not find an elusive water leak and narrow down which fitting it was, I would tie cotton rag around under what could be suspicious. About 1/3 of a dish towel size.
    That would be each riser coming up thru the floor etc.
    These things don't leak if you are watching them.

    The cotton rag stores the evidence for hours.
  • cubicacrescubicacres Member Posts: 302
    Thanks, we added some rags to narrow down which fittings & pipe sections/elbows near the ceiling in the basement it might be leaking from & will check for dampness periodically. The 1st floor tennant agreed to put some paper towel under his floor estuchion plate on the riser to verify if it's the radiator valve or below his floor causing the leaking. Glad to learn the riser just went a few feet up to a single radiator on the 1st floor without feeding another radiator on the 2nd floor, so we've narrowed it down to minimal inside-wall cavity pipe replacement issues we were concerned with originally :)
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