Welcome! Here are the website rules, as well as some tips for using this forum.
Need to contact us? Visit https://heatinghelp.com/contact-us/.
Click here to Find a Contractor in your area.

Leaking Relief Valve - urgent or non-urgent replacement needed?

docancho
docancho Member Posts: 38
I have noticed that relief value has been leaking a little constantly on my McNeil hot water boiler for heating. is this something urgent I would need replacement/fixing or it can wait until next time boiler guy comes for any maintenance?

last year I had expansion tank replaced so it's practically new.

the only thing i have noticed is little water on the floor but I have drain next to it so it's not a big deal.

thanks.

Comments

  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    Have it fixed now. Losing any water means the boiler pressure is dropping, and who knows if the water feeder is working/creating an unsafe condition.
  • docancho
    docancho Member Posts: 38
    boiler pressure constantly stays on 20psi which plumber said its fine. (3 separate zones)

    I will keep an eye out for next few days if anything changes because boiler has been ON but weather is warm so boiler barely kicks in
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    Ok, just know that the fresh make up water isnt doing any favors- introducing entrained air that can make heat emitters airbound and eating up iron. Good luck!
  • icesailor
    icesailor Member Posts: 7,265
    Did the "plumber" check the pre-charge pressure of the new expansion tank? If should be at least 18#. Is it big enough? If it is a cold start boiler with a lot of radiation, it needs to be equal to a #60 Extrol. Or at least another #30 type added.

    You need to take the system when it is cold, and start it. Let the entire system get hot. If the system pressure starts rising to 28#, there is not enough expansion area.

    Post photo's of the boiler and the expansion tank connections.
  • docancho
    docancho Member Posts: 38
    He did check on both -- expansion tank and relief valve. he's been plumber for 25+ years and comes highly recommended.

    he said if this continues to keep leaking, we will need to replace either value and/or both value and expansion tank. I have replaced expansion tank last year and not sure how long they last. before new one, I had one for 6+ years.

    He's good but pricey at same time. I am just checking if this is something that I would need to call him ASAP to fix or something that he can replace down the line in case he comes to check up on something else.

    it does not bother me other than I see little water to the side of boiler.
  • icesailor
    icesailor Member Posts: 7,265
    edited October 2014
    "Just because you are handling a lot of money, doesn't mean you are making any".

    Just because you have been doing something for a long time, doesn't mean you know everything.

    Either the fill valve needs to be replaced, or it doesn't.

    If you changed the Extrol Tank and the problem still exists, either there is nothing wrong with the tank, it needs more expansion area, or the fill valve is bad. Once the PR valve starts leaking, it almost always needs to be replaced.

    My wife has had horses her whole life. We lost 7 horses (dead) that developed the same symptoms and had to be put down, into the ground. We had a Veterinarian who treated all 7 in every way he could come up with. Nothing worked. We came up with a treatment. He would have no part of any suggestions because no horse was ever sick the same as the ones before. In his opinion. But they still had to be put down. We started treating them with the way this problem is now treated. We have never lost another horse as long as we could get the meds. If you asked the vet today about this problem, he would claim that he has never EVER seen any case like these. But today, if he sees a case like the seven he says he never has seen, he treats them like we did and do.

    PR valves "leak" for a reason.

    DanHolohan
  • docancho
    docancho Member Posts: 38
    Is replacing pressure relief value something that can be done with basic knowledge or it involves a plumber?

    from my research on net, replacing it does not require much expertise unless I am wrong -- basically, shutting down water supply to boiler, shutting down boiler, relesing some water and waiting for water to cool down, unscrewing/removing bad PR valve, wrapping teflon tape on new one and screw it in same place - turn the supply water and boiler back on.

    unless I am missing something, this seems very straight fwd.
  • Bob Bona_4
    Bob Bona_4 Member Posts: 2,083
    A pro can better determine if the prv was dripping from age, or overpressurization and the cause of that. There still may be a problem, and there may be air in the heating loops now.
  • billtwocase
    billtwocase Member Posts: 2,385
    I would like to see pics of piping, tank location, etc. As stated above, that valve released for a reason. What source for hot water? Indirect, tankless? I would also agree with Ice about experience. It can be just a number. Don't be a cash cow
    DanHolohan
  • Rrey
    Rrey Member Posts: 18
    Causes of PRV leaks:
    Bad prv. If it's leaking aND the pressure is below 30 psi, it's bad.
    If it's leaking and the pressure is 30 psi or more, it's just doing its job.
    Can be a bad expansion tank but since it's new, it sounds like he missed the cause.
    A bad fill valve can over fill the boiler. Also a leak in a domestic hot water coil or indirect water heater.
    Another cause that is commonly missed is the boiler fill on the return piping. The circulator kicks on and drops the pressure at the fill, kicking in the fill valve which causes the boiler to activate the prv when hot.
  • icesailor
    icesailor Member Posts: 7,265
    "" Another cause that is commonly missed is the boiler fill on the return piping. The circulator kicks on and drops the pressure at the fill, kicking in the fill valve which causes the boiler to activate the prv when hot. ""

    In my experience, there needs to be a really bad screw up of monumental proportions for that to happen.