Problem with whole house pressure relief valve? Need advice from a pro. :)

Discussion in 'Plumbing Forum, Professional & DIY Advice' started by Patriot_RAM, Jan 11, 2012.

  1. Patriot_RAM

    Patriot_RAM New Member

    Messages:
    3
    Location:
    Arkansas
    Hey Guys,

    I should have looked into this sooner, but there's a drain pipe outside my house that is constantly running water. It's close to the a/c drains that also run water all summer long, but this doesn't go to the a/c. I traced it back in the house the best I can, and it looks like the source of the water is the output from avalve that looks just like this one: http://amzn.to/xzwyg0

    Over the past couple weeks, the water running out has grown from a very small steady stream and is now up to a good quarter inch or more. My water bill is up to almost 13,000 gallons. Normally, we use about 10k. (there are eight of us in the home...)

    What is the easiest way to test the pressure in the home to see if it's just too high, or whether or not the valve is defective? What should the pressure in the home be? Can you hook something like this http://amzn.to/yVilM1 up to the outside faucet to get an accurate pressure reading?

    This valve is located about 18-20 inches downstream of the whole house pressure regulator. I do know for a fact that dirt got in our lines about a year and a half ago after a main break on our street.

    Let me know what your thoughts are. Thanks in advance for your help!

    Patriot_RAM
  2. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,360
    Location:
    New England
    A couple of things: first, you can pick up a screw-on water pressure gauge with a second (tattle-tale) hand to show peak pressure at any plumbing supply or big box store for around $10 or so. You can get one that will screw onto a hose bib (maybe the drain on the WH, or the washing machine connection, or with adapters, anywhere). Pick one up and check. Any reading, either peak or static above 80psi requires a PRV... the PRV from the factory is probably set at about 50psi, but it is adjustable.

    The relief valve may just be doing its job. If yours really is adjustable, you could try raising the opening point.

    A home with a PRV should also have an expansion tank or as in your case, with the pressure relief valve, wasting a bit of water each time the WH ran after hot water useage. While a PRV can be serviced, since that doesn't always fix it and labor is expensive, it's generally better to just replace it when it fails. You don't need that relief valve, but it doesn't hurt. If the PRV and expansion tank are working, that valve would never open. It is a second, or third, depending on how you look at it, means of maintaining pressure: the T&P on the WH will open if the pressure gets to 150#, the expansion tank (when present and working properly) will prevent the water pressure from rising as a result of heating water, and third, that pressure relief valve, which may be gummed up and now stuck open.

    In the interim, you might just cap it. I'd consider picking up a Sharkbite cap to limit your water wastage until you figure out the rest. Those are easy to install, take no tools, and can be removed fairly easily. You do need either their tool (it may come with it), or a pair of pliers or a wrench to compress the latch so you can remove it.
  3. Patriot_RAM

    Patriot_RAM New Member

    Messages:
    3
    Location:
    Arkansas
    I remember the journeyman working on this home making a comment during the new construction plumbing work. He said that state law allowed the user of a PRV without an expansion tank. That being said, the only PRV I have is on my raidiant heat, which is isolated through a heat exchange and not even part of the fresh water system.

    I'm going to get a gauge and check out the pressure and try adjusting the PRV first if I can figure it out. Sounds simple enough. Either the water pressure is too high, PRV is too low, or it's dirty / defective in some way.

    It doesn't seem to leak based on when the water heater runs. That pipe has a 1/4" stream 24x7. Sounds like I should get to work. :)

    Thanks for the help!

    Patriot_RAM
  4. jimbo

    jimbo Plumber

    Messages:
    8,997
    Location:
    San Diego
    Regulator valves do not go out of adjustment. If the pressure is too high, ( and not related to expansion) the PRV needs to be replaced. The valve you show , of course , is a RELIEF valve, not the regulator. The only application I am familiar with for that type of relief is for water heaters which replace the normal TP with a watts 210 hi temp gas shut off. THAT valve requires a separate relief.
  5. Patriot_RAM

    Patriot_RAM New Member

    Messages:
    3
    Location:
    Arkansas
    I was talking to somebody when I wrote this. What I meant to say is that my only expansion tank is on the radiant system. There isn't one on the fresh water system. It only has a PRV that drains outside the home. I'll post a picture of the setup.

    Thanks!
  6. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    You had a good plumber that saved you from an expansion tank. But your valve is adjustable and you can simply turn the adjustment tab to a higher PSI [ perhaps 60 or 80] to shut it offf. Other wise you just need a new one.

    You might lose at most a quart a day with the valve working correctly.

    Here is a dedicated version: http://www.watts.com/pages/_products_details.asp?pid=564
  7. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,311
    Location:
    Cave Creek, Arizona
    quote; Regulator valves do not go out of adjustment.

    If that were true, we would never have to replace them. Also, a "good plumber" would have installed an expansion tank rather than a relief valve and it would have been less expensive given the cost of the valve and its discharge line.
  8. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    Everything goes out of adjustment, even us. But I prefer a good SS spring, a fine quality seat or washer, over a shower curtain in a folgers can. It would llikely have failed for the guy by now and his 150 psi WH heater valve would be the release. Or more likely his washer hoses.

    You can use pex for the discharge. Do them BOTH like NASA would.
  9. Hackney plumbing

    Hackney plumbing Homeowner

    Messages:
    1,174
    Location:
    Alabama
    Never advise anyone to cap a water heaters relief line. In the right situation that could blow up and kill people. See how dangerous taking advice on a forum could be?
  10. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,360
    Location:
    New England
    This isn't the WH relief line, it's a relief line installed after the PRV in lieu of an expansion tank. The T&P is still there, unless I'm misreading things entirely. But, I agree, capping the T&P line is asking for the house to blow up.
  11. hj

    hj Moderator & Master Plumber Staff Member

    Messages:
    27,311
    Location:
    Cave Creek, Arizona
    Besides, many relief valves are designed not to be "tight" under backpressure so that if they are capped they will leak somewhere to indicate that there is a problem.
  12. jadnashua

    jadnashua Retired Defense Industry Engineer xxx

    Messages:
    22,360
    Location:
    New England
    Give me a break...I suggested capping that as a temporay measure until the problem was found and corrected. I also told him how to remove it. He was dumping a constant stream of water which was costing him. If it failed to stop the water by leaking somewhere else, it would still be easily reversable.

    Just to reinforce what was said earlier...NEVER cap the output of a T&P valve, it could kill you and your family and destroy your house if the WH failed. This was not the T&P valve being capped.
  13. ballvalve

    ballvalve General Engineering Contractor

    Messages:
    3,261
    Location:
    northfork, california
    His valve is adjustable. the first step is to get a pair of channel locks and tighten it up.
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