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Weil McLain gas Overflow pipe is dripping, I think also high temperature

Multiman
Multiman Member Posts: 8
edited March 30 in Oil Heating

I have a 3 family building in which one boiler's overflow pipe is slowly dripping water. It is just coming out of the overflow pipe, not out of a crack anywhere. The temp of the water on the gauge was pretty high, read at about 210 degrees F, as opposed to 170 F on the other boilers. The psi was around 22, kpa 150. The system only supplies baseboard hot water heat, not domestic hot water. As the unit is vacant now, I turned the apt heat thermostat very low, hoping to shut off the boiler that way. My handyman who can take a look at it is just leaving for a 2 week vacation. Can this wait until he gets back, or do I need to call in a plumber now?

Comments

  • Jamie Hall
    Jamie Hall Member Posts: 25,966

    By "overflow pipe" do I presume you to mean the pressure relief valve?

    This is not good. The most likely problem is that the aquastat has failed, but there are other reasons why a boiler would overheat, and it would be a very good idea to figure out what the problem is… BEFORE you try to run it again. Since the unit is vacant, are you far enough south you can just turn it off and leave it off?

    Br. Jamie, osb
    Building superintendent/caretaker, 7200 sq. ft. historic house museum with dependencies in New England
    Grallert
  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,673

    I would shut the boiler off until you can have it looked at. Your water pressure is a little high. You could have a bad gauge, a bad pressure relief valve a bad expansion tank. Probably not all 3 at once but it needs to be checked by someone compatent

    EdTheHeaterManSuperTech
  • Multiman
    Multiman Member Posts: 8

    Thank you. Yes, I can shut it off for the season now. I'm looking for an HVAC plumber in Central CT (New Britain, not far from Hartford) to check it out.

  • HVACNUT
    HVACNUT Member Posts: 6,739
    https://forum.heatinghelp.com/discussion/comment/1850587#Comment_1850587

    If the leak is from the boiler pressure relief valve, then there's a few things to check. The relief valve is rated for 30 psi. The gauge reads 22 psi. So it's either a faulty relief valve, or a faulty tridicator gauge. Have the pressure checked with an accurate pressure gauge. I'm leaning towards a bad gauge. The 210° is high, but it shouldn't raise the pressure to 30 psi unless there's a failed extrol tank, a full expansion tank, the Pressure Reducing Valve is dirty and therefore not reducing, or a hole in a heat exchanger for domestic hot water.

    Were the boilers serviced recently? Is it possible someone raised the limit temperature on that boiler but not the others?

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 17,673

    @Multiman

    PM @Charlie from wmass he may be too busy because he is in demand.

  • Multiman
    Multiman Member Posts: 8

    Had the pressure relief valve replaced, and the temp had been set too high, maybe because otherwise that apt was not warm enough, but I won't find out until next winter, I guess.

    HVACNUT
  • Multiman
    Multiman Member Posts: 8

    No more leak. Pressure is down to about 12. But the temp is still over 200, like 210, despite having been reset go 170. It is a combo gas and domestic hot water unit. What could cause it to run hot like that?

  • HVACNUT
    HVACNUT Member Posts: 6,739
    https://forum.heatinghelp.com/discussion/comment/1852577#Comment_1852577

    What model boiler and aquastat? Are you sure the temperature reading is correct?

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