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.

Reilef valve problem


(no kidding, one I got today)

175 PSI street pressure with no pressure reducing valve at the service?

I don't think those boiler feed valves like that much pressure on them.

Just shooting suggestions out there...



  • nick z.
    nick z. Member Posts: 157
    Reilef valve problem

    Factory reilef valve was leaking on Wm-Mc oil Fired I installed about 18 mos. ago. I replaced it with a new Watts.Press. read 12lbs before and after I replaced the valve.Everything was fine so I left. Couple days later cutmer says its leaking again.Surer than poop it was press. still read 12,Press gauges drops down a little when circ. runs ,so I fugured my luck to get a bad valve.So I replace it with another on New years eve day. Custmer let me know today new valve is also leaking, gauge still reads 12.
    Could the press. gauge be that far off? I would know what to look for if the press. was high but its not. I can't check the gauge to easy because it s a palin steel tank.Any thoughts? Thanks Nick
  • Mark Hunt
    Mark Hunt Member Posts: 4,909
    What type of expansion tank?

    And does there happen to be a domestic coil or indirect fired water heater on the system?

    Mark H

    To Learn More About This Professional, Click Here to Visit Their Ad in "Find A Professional"
  • jim lockard
    jim lockard Member Posts: 1,059
    1st thought

    would be to remove the relief and install a tee then replace the relief and put a new gauge in the branch of the tee. This should help you to troubleshoot the system a little better.
  • nick z.
    nick z. Member Posts: 157

    Plain steel exp. tank,yes there is a coil.Press. gauge never reads above 12lbs. when vavles have been leaking.
  • Good point Noel

    I think the Taco pressure reducers specify the house pressure to be less than 100 psi. Was the 175 psi. in a residential home ? I bet water running through those pipes sounds like a locomotive .

    I keep a cheapo pressure gage that can connect to any hose drain . I saw the same one in Ace hardware for less than 10 bucks . Comes in handy for these situations .
  • Rookie
    Rookie Member Posts: 175
    Relief valve

    Maybe the valve is doing it's job, if you are replacing the valve why not the pressure gauge, when you drain the boiler did the gauge go to zero?, what was the air pressure in the expansion tank (bladder type)?, maybe just recushion the steel expansion tank.Check the boiler feed valve is it up to snuff, do you have a tankless coil or a indirect?, where is the pressure coming from?Take a washing machine hose connect it to your boilers draw off, screw a 1/2 x 1/4 bushing on a mip draw off, then put a 60 psi gauge on the other end attach this to washing machine hose( double end female hose connector) check your pressure, keep and eye on it.
  • Big Ed
    Big Ed Member Posts: 1,117

    Three valves and still leaking ? First you need a new tridicator gauge.

    Now if the valve is leaking with a constant drip.. Make sure your installing a 30 # relief and not a 15# pop safety....No then........Change the feed valve first , then check the coil... Ask home owner if any plumbing been done around the same time problem has started...

    Drips on temperature rise, you have a expantion problem. Tank water log , tank lost charge or not enough expansion tank......

    Pressure increases when circulator runs....bad location for pressure reducing valve or feeder...

This discussion has been closed.