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Community and Q&A

Multiple plumbing issues and water heater questions

John Sexton | Posted in General Questions on

Hi all,

I have a few issues surrounding my plumbing and hot water heater and the behavior of it and optimization of the system. I will use bullet points below because I am not certain that all of the issues are related, but want to get thoughts on each.

The components of the system are as follows on a 20 year old, ~6400 sq ft two level house.:

The water line enters the house on the right side, goes through a pressure reducer (not sure if it even works anymore) and then through PEX across the entire width of the house and into the left side garage, where it goes through some Aquasana filtering, a Us water systems salt based water softener, and then into the hot water heater or cold water for the house.

There is a Grundfos UP15-10B7 Circulator pump on the hot water heater, and the water heater is a State Industries GS6-75-XRRS with an expansion tank. All of this, except the Aquasana and the water softener, was installed before we moved in last year. I think the water heater was installed in February of 2016.

Here are some of the issues:

1. Recently I have noticed a good bit of water coming from the relief valve / pipe and onto the floor of the garage. I put a bucket under it and it has filled a roughly 2 liter bucket in a week’s time. I have tried turning down the heat on the unit, but to get it low enough to where I don’t “think” I am seeing much new water, the water is too cold in the house and my wife and kids complain. Is this likely a malfunction in the tank, or could there be another reason? I had thought the expansion tank was supposed to fix these issues…

2. The first shower of the day is quite a bit colder than the rest. I assume this has to do with the circulation pump and the water staying in the long maze of pipes instead of the hot water heater? Would a timer or something on the pump fix this, where it only starts recirculating a couple of hours before we get up in the morning? Other ideas?

3. We have had pretty bad water hammer in the house since we moved in a year and a half ago, and have yet to really fix it. I have done many of the suggested remedies (cutting off the water supply, bleeding from all the taps in the house starting with the upstairs and furthest, etc.) I also installed water hammer arrestors on the washing machine hot and cold inlets, as these cause a LOT of hammer, but even those did not keep it from coming back pretty quickly. I can pretty easily create water hammer in the house just by turning faucets on and off, despite that the water pressure at the faucet is not higher than normal. Some are even somewhat low in my opinion.

4. I did try last night to just unplug the circulator and see what happened this morning. It took a solid 4 or 5 minutes for hot water to flow to my master bath shower (on the other side of the house from the garage hot water heater) and the temperature never rose to the normal level we are used to.

I do think I need to get the pressure valve replaced, as I had a cheap pressure gauge from Home Depot that I put on the hose spigot and was getting a reading over 80, or even 90 or so, but it broke pretty quickly and filled with water, so it was likely unreliable. I do think the water pressure is too high coming into the house, though, even though I do not have excessive pressure in the shower or in the house. I worry that reducing it at the source may take too much away inside.

Thanks so much for any advice!!


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  1. John Sexton | | #1

    Adding picture

  2. Norman Bunn | | #2

    Your expansion tank may be defective. Do a Google search on how to test.

  3. User avatar
    Dana Dorsett | | #3

    Tap the top of the tank- it should ring. The bottom half will thud, since it's full of water.

    If the top half thuds, press the air valve- does it spit water, or only air? If water, the diaphram is shot. If it's completely dry air it may have lost air pressure and simply needs to be re-charged to the appropriate pressure so that it can allow sufficient expansion room for the water volume of the system (most of which is the tank.)

  4. John Sexton | | #4

    I tested the valve and air comes out.

  5. User avatar
    Dana Dorsett | | #5

    What is the water pressure at your house, and what is the air pressure on the tank (both measured with a cold-tap running at 0.5-1gpm to relieve any static pressure left over from the tank heating)?

    The pre-charge on the tank needs to be at or slightly above the pressure of the water in your house in order to function correctly. If the water is dribbling at a faucet you should be able to add air to the tank until it's a handful of psi above the water pressure. If it it stays at the water pressure no matter how much air you're adding the diaphragm is shot, but the fact that you only get air when releasing at the air valve is an artifact of the orientation of the tank air-side-up.

    If you can pump the air side to ~5 psi above the water pressure and the tank is already at temperature, it will probably be a sufficient charge for preventing overpressure spikes.

  6. User avatar GBA Editor
    Martin Holladay | | #6

    There are lots of issues here, so you may want to hire a plumber to help you with the testing.

    Obviously, it would be good to know the water pressure in your house, and whether your pressure-reducing valve is working.

    Old pressure-temperature relief valves (PT valves) sometimes fail. You may need to replace the PT valve on your water heater. PT valves come with different temperature and pressure ratings, so make sure that you install the right kind of PT valve.

    You need to understand the circulation pump on your water heater. This system is probably an energy hog. Ideally, you will control the circulation pump with a switch in your remote bathroom, so that the pump only come on when there is a demand. Here is a link to an article on the topic: .

  7. Jon R | | #7

    You should move your pressure regulator to be after the filter and softener.

  8. John Sexton | | #8

    Thanks everyone. It sounds like my first move is to get another pressure gauge that hopefully will not break quickly this time. Any suggestions as to brand or model?

    I can measure the pressure at a spigot that is right by where the water comes into my house from the street and the line just T's off of the main line. Then I can measure the "after all plumbing and PT valve" on the spigot at the other side of my house.

    So I should NOT have a pressure regulator BEFORE the Aquasana filters and the water softener? I think the manual or somewhere on their site indicated that the pressure should not be all that high entering the devices....

    As for a plumber for the rest... are "general" plumbers good at diagnosing water hammer, possible issues with the expansion tank, and installing any enhancements to the circulation pump? Or are there certifications I can look for to know I am getting a "better" plumber? Living in Nashville, there is certainly not a shortage of places I could call...

  9. Timothy Tucker | | #9

    For water hammer -- assuming that you get the pressure issues resolved and still are having trouble -- you could go the extra step of adding in-line hammer arrestors on all the faucets / toilets / etc.

    At ~$16 each in bulk for something like a 3/8 inline model like a Sioux Chief 660-GTR1, it might be worth a try.

  10. Timothy Tucker | | #10

    I'd be wary of installing the pressure regulator after the filter / softener without having a clear understanding of what pressure is coming in from the street & what they're rated to support.

    To expand on my previous recommendation -- I'd also hold off on adding more arrestors until you're sure that the pressure is under control. If it's too high and they fail from the excess pressure, you're right back where you started.

  11. John Sexton | | #11

    I don't know enough about all the terminology or what I am looking at unless the check valves are labeled as such, but I will take a look.

  12. User avatar GBA Editor
    Martin Holladay | | #12

    They look like check valves to me.


  13. Andrew Bater | | #13

    John, are those check valves at the wall?

    If so, perhaps your issue is explained here:

    Edit: The presence of the ground wire on that same bit of piping makes me think that is the input to the tank; the check valves isolate flow between your cold water supply and the return from your circulating pump. Guessing the check valve with corrosion and no insulation is the cold water supply.

  14. Andrew Bater | | #14

    FYI, this is the pressure gauge that I have had forever; I last used it when replacing the pressure reducing valve in my previous home, probably 20 years ago. Just tried it now, still works. Less than $20.

    Available here:

  15. John Sexton | | #15

    Hmm that looks just like the one I bought that filled with water... oh well maybe I just got a bad one.

  16. Tom May | | #16

    1..leaking relief valve....lift the lever on the valve to flush out the spring and seat...if it still leaks...replace it....15 bucks... that the relief valve is fixed turn up the temp on your water heater to get a hotter shower. Check the anti-scald setting on the valve itself..if set low then it doesn't matter how high your turn the hot water heater temp....which may have been the start of problem 1.
    The pump, on what i see as a gas water heater, is most likely a recirculating pump for fixtures 100 ft away....can't think of any other reason it is there but the piping to it doesn't look right. Pump should be in series with a return line, teed off the hot water line, from the far away fixture returning into the cold water side, not installed on the hot water outlet.
    Plus no vacuum relief valve either, and you don't see expansion tanks on HW tanks to obviously whomever installed the tank doesn't seem to know what they were doing. Where do those two lines with the check valves go? Is that the cold water inlet side?

    3. If every faucet causes the water hammer, then there is most likely a piece of broken faucet washer somewhere in the line..... try to isolate area, remove shut off stems and try to flush out.

    4. See 2.

  17. John Sexton | | #17

    Thanks, Tom. Is there a way to hire a plumber with confidence that he could look at all of the issues and not just be a random kid the company sends out? Someone who could and would diagnose and fix all of these issues, including possibly redoing the pump and expansion lines?

  18. Tom May | | #18

    Find a plumber who works for himself with no employees....or retired and still working...or ask your neighbors...

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