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  1. #1
    Join Date
    Sep 2007
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    Question Leaking pressure valve on indirect hot water heater

    Just a few days ago I noticed that our 1-month old indirect hot water heater's pressure release valve has been dripping when we use the washing machine. This isn't just a little drip drip. It's a thin stream of water that comes down for about 30 seconds and then keeps dripping for about a minute. It happens about a minute after the boiler finishes heating up the water in the IWH. Again, it seems to only happen when we use the washing machine; it doesn't occur when we use the dishwasher, shower, or any other hot water faucet.

    Any ideas?

  2. #2
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    Sep 2007
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    Default Re: Leaking pressure valve on indirect hot water heater

    I have to amend my previous post. Some water is dripping whenever we use the dishwasher and perhaps the shower. Not as much as when we use the washing machine, though.

  3. #3
    Join Date
    Aug 2007
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    443

    Default Re: Leaking pressure valve on indirect hot water heater

    This could be caused by any one of several things.

    Since it's a new installation, if you have hard water, sometimes minerals deposit on the TPRV & it opens when hot water is produced when a washer or dishwasher is used.

    Often, you can open & close the valve several times to remove the caked on minerals.

    The TPRV is tied into the house water pressure; if you have well water with a pump that varies the house water pressure (should be 60 psi or below), this could open the TPRV.

    Similarly, if you have city water that varies in pressure, or is above the pressure stated, this could also open the valve.

    Sometimes the thermostat on the indirect WH is set too high & can dropped down to 120-130 degrees.

    Do you have a pressure reducing valve on your city water, or a pressure regulator on a well water pump???

    One may have to be installed, if not.

    Sometimes a 50 psi expansion tank has to be installed on the HW line to absorb some of the excess pressure.

    Do you have the original installer or a service person you can call to take a look at it???

  4. #4
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    Sep 2007
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    12

    Default Re: Leaking pressure valve on indirect hot water heater

    Quote Originally Posted by JacktheShack View Post
    Do you have a pressure reducing valve on your city water, or a pressure regulator on a well water pump???
    I'm really not sure if we have a pressure regulator. Is it this?


    This is what our main water feed looks like:


    Sometimes a 50 psi expansion tank has to be installed on the HW line to absorb some of the excess pressure.

    Do you have the original installer or a service person you can call to take a look at it???
    I believe we have a 50 psi expansion tank. It's the big blue-green tank at the top of this picture, right?


    After our previous painful experience with the plumbers, I'm reluctant to call them again. I'm gonna try to deal with this myself first.

    I'll keep you posted. Thanks.

  5. #5
    Join Date
    Sep 2007
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    12

    Default Re: Leaking pressure valve on indirect hot water heater

    Sorry for the tardy reply. Got sidetracked with other matters. I'm about to try purging the pressure release valve on the hot water tank. I hope that works.

    Quote Originally Posted by DwarfWytch View Post
    Was this indirect hot water heater installed after you had a resolution of your too-high pressure water hammer problem (resolved with new check valve and a pressure reducing tank) or before?

    If before - suspect you are having failures resulting from the formerly too-high water pressure and excessive pipe movement. I recall somewhere in one of your previous posts you said a watts pressure reducer was installed on the hot water side of your water heater (and elsewhere on the cold water inlet, later replaced with an expansion tank) was it installed on this one?
    The indirect hot water heater tank was installed before the hammer problem. The expansion tank and hammer arrestor were installed on this one.

    Quote Originally Posted by DwarfWytch View Post
    I thought you said on your other post string that you have city water - looks like a picture of a water meter to me (Rockwell perhaps?).

    Did you ever get around to bleeding your heating system of its trapped air?
    Why would having a water meter mean that we don't have city water? Sorry, but I'm not familiar with how the water system works. I'd welcome an explanation.

    Still haven't gotten around to bleeding trapped air out of our steam heating system. Big procrastinator here. Is this the valve that I should open? Do I just lift the lever?



    Quote Originally Posted by DwarfWytch View Post
    Perhaps this is covered under your "plumbers'" installation warranty, since likely the manufacturer won't if you had too-high closed system pressure problems before. Has it been a month already since they were last in to "tinker" with things?
    It's been over a month since the plumbers were last here and over 2 months since they installed the water heater, so I'm sure the installation warranty expired. If I have to, I'll call them and see if they'll fix it under the manufacturer's warranty, but I bet they'll charge me for the service.

    What I didn't mention in my other thread is that the plumbers neglected to give me a price quote when they installed the expansion tank and check valve. I was told that it was covered under their installation warranty (which doesn't make sense in hindsight). Imagine my shock and outrage when I got a bill in the mail a couple weeks later amounting to over $9,000! When I called, I was told that it was a clerical error and should be about $400, if I recall correctly. I don't mind having to pay for the parts, but what a lousy way to go about it! Now you can understand my reluctance to call them back.

    Quote Originally Posted by DwarfWytch View Post
    P.S. since you had some horrible troubles in the past (other post string), I'd expect if you have any single handled mixing faucets in the house you may develop some issues with them in the near future if you haven't already (cross-over).
    Ummm, what? I don't think I understand what you mean.

    OK, I'll let you guys know what happens. Thanks again for your advice.

  6. #6
    Join Date
    Sep 2007
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    12

    Unhappy Re: Leaking pressure valve on indirect hot water heater

    Well, I just had a visit from our oil provider's service tech for a regular boiler cleaning. He told me that the leaking pressure release valve is probably caused by the fact that there is no expansion tank on the hot water line. He recommended that we get a high-pressure high-temperature 15-gal expansion tank (15-gal or 15 lbs, I'm not sure now). Does this sound right?

    I tried opening and closing the valve several times, but it didn't have any effect on the leaking.

  7. #7
    Join Date
    Sep 2007
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    12

    Post Re: Leaking pressure valve on indirect hot water heater

    OK, I lowered the thermostat (aquastat?) in the water heater tank from 125 to about 120 degrees. Can't be sure because there are only 3 markings on the dial, one of which designates 125 degrees. Looks like that helped because there's much less leaking. However, there is still some leaking, but I can't pinpoint when or why it occurs. It doesn't always occur when we use the dishwasher, washing machine, or shower anymore.

    Should I lower the thermostat a little more? What's the ideal temperature?

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