Groaning Pipes

The Tank Groaning Pipes

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    On Saturday, I drained and flushed my water heater, replaced the heavily calcified element and insulated the tank. Everything seemed to go well and we have plenty of hot water. I even used a meter to make sure both elements were firing properly.

    Then on Sunday I noticed a groaning from the pipes. My first thought was some debris in the hot water line, but it makes the noise when I open a cold water tap too. I cannot pinpoint the noise, even when my wife runs the water when I’m in the basement near the pipes.

    It sort of sounds like a low flying plane passing over the house. The sound starts about 10-20 seconds after opening the faucet and then ceases 10-20 seconds after closing the faucet. My first guess is the pressure regulator, but I guess it could be the expansion tank too. This is my first house with an expansion tank, so I don’t really know how to evaluate them.

    Anyone have any suggestions how to diagnose the sound or pinpoint it better.

    My last house had a noisy pressure regulator, so that is my prime suspect. However, the expansion tank could be doing something I guess.

    Larry Weingarten

    Hello: Put a pressure gauge on the water heater drain or any bibb downstream of the regulator. When plumbing groans, it’s usually vocalizing a complaint about pressure. Sometimes it’s just grousing 😎

    Let us know what the gauge tells you and the pattern it exhibits. That will help in figuring out what the plumbing is trying to tell you.

    Yours, Larry


    I have a gage, I’ll try to check it this evening. I think it was somewhere between 50 & 60 last time I checked.


    Make sure all shutoff valves are fully open.


    We’ll I finally found my gage. The pressure ranges from 55 to 60, and the peak indicator said it went to 62 overnight.

    I tried to repeat the sound on Thursday night and only got a slight chirp/squeal from the pressure regulator when I opened the new ball valve on the water heater.

    However, Friday evening the sound returned. It happens only under specific flow that is difficult to reproduce. But I think I can reproduce it. The sound is easiest to create by opening two cold taps in the Mbath, or flushing the toiliet and opening a single tap. The sound starts quietly, peaks after about 5-10 seconds, and then dissapates after closing the faucet tap.

    I’m leaning towards the pressure regulator. Last time I had a chattering regulator, I had to play with the setting to find a low-noise sweet spot.


    I’ve tried adjusting the pressure up or down, but the groaning from the regulator returns within a few minutes at almost any setting.

    I’ve heard that dirt or debris can cause chattering and the regulators can be cleaned. Is it worth the effort to try to disassemble and clean? I’m worried I won’t be able to reuse the rubber parts and replacements may be difficult to find.

    I have unions at both ends of the regulator and it looks like a standard 3/4 size (25-75 psi).

    Anyone have experience with this?



    It took me a while to accumulate all the parts.

    I purchased a few new ball valves to replace the globe valves, a new pressure reducer/regulator, a new annode, new dip tube, dielectric nipples, and some flex pipe to create my own heat traps.

    State makes a Turbo dip tube that actually curls about halfway around the bottom of the tank, so I ordered their tube because it looked effective. We’ll see how it does.

    I removed all the globe valves in the main line and hings went okay sweating in the new ball valves. I took down the expansion tank and adjusted the pressure from the factory setting (40) to my preferred pressure of 65psi. I suspect the plumber didn’t really do anything but install it. I also installed one of the surplus globe valves on the line to the expansion tank so I can service it without draining the whole system.

    Replacing the anode was easy, but even at 3 years old the AL annode was toast. Installed new Mg annode.

    Removing the old heat trap nipples was the hardest part. The were both gunked up with black sludge and rust from the steel unions above the nipples.. Very little of the nipples were protruding above the foam insulation. Even with two people I couldn’t get either of them to budge. I eventually had to slice the nipple to break the contact with the threads and the hardening sealer they used. Two things went wrong in the process. On the hot side the check valve got pushed into the tank and on the cold side the original PEX dip tube got pushed into the tank as well. I figure the PEX shouldn’t be too harmful, but it was still disappointing.

    The icing on the cake was the replacement nipples were much shorter than the originals. So I had to make a run to the store and add and extension to the nipples. As long as they don’t leak, I think I’m okay, but well see.

    I’ll let things settle down a bit and then maybe take the lower element out and see if I can snag any pieces or parts and pull them out.

    I guess the bottom line is the groaning noise is gone and the system seems to be flowing much more smoothly.

    Larry Weingarten

    Sometimes people just don’t realize how much fun plumbing can be 😛 So, it sounds like the groaning could have been caused by either the reducer or possibly by loose washers in the globe valve/s.

    Persistence is a good trait to have for anyone doing plumbing.

    Yours, Larry

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