plumbing pipes are singing what's the cause?

[rfuerst911sc]

Went to my sons house over the weekend and he said his plumbing pipes have started making a groaning/singing noise recently. His house is two years old and has not exhibited this condition until recently. I heard the noise and it sounds like a horn going off. I went in his basement and surveyed the plumbing and noticed there was an expansion tank installed. We tried altering the precharge of air in the tank but couldn't get it to take a charge. Thinking the tank/bladder was bad we bought a replacement for less than $40.00 and installed it with no difference in the noise. We checked the water pressure at a outside spigot and it was 100 lbs. and we set the expansion tank pressure to 80 lbs. which the instructions said is the max it should be set to. I asked my son what the hot water heater was set to temp wise and he stated 125 degrees. I'm baffled to figure out what has changed to cause this condition, any ideas? I'm guessing air in the lines but not sure how to fix this? Any suggestions appreciated.

[Red88Carrera]

100psi pressure is way too high. Should be no more than 60psi. If the expansion tank has 80psi, and the incoming is 100psi, the expansion tank isn't doing anything. If you are on city water, see if the neighbors have the same problem. If there is a pressure reducer in the system, set it to 60psi. If not, install one. 100psi will cause premature failures to the faucets, toilet valves, dishwasher, etc. You will get all kinds of noises with 100psi in the system.

[914GT]

I've had toilet valves make a groaning noise when they get worn, and it would be worsened by the high pressures you have.

[sammyg2]

The expansion tank will work a little if it's charged to 80% of the water pressure but 50% would be better (charged with no water pressure on it of course).
See if there's a water pressure regulator on the system and back it down. 60 psi should be plenty. Then reset the charge on the expansion tank. If there isn't a regulator, put one in. That should help.
Or, maybe the regulator is what it making the noise? Just a thought.

[Zeke]

+1 on both above.

[rfuerst911sc]

My son has checked with neighbors and no one is saying they have this issue. It is city water not a well. If there is a pressure regulator generally where are these installed? What do they look like?

[Hugh R]

It's usually a bell shaped think at the main to the house. You have a screw on top with a locknut. I think you screw it in to reduce pressure.

[ed martin]

I do believe that if pipes are not braced or fastened properly to the studwall structure, I think that could part of the problem. The contractor/plumber cut corners perhaps?

[Scuba Steve]

I'm used to seeing them installed just in from the water meter.

[sammyg2]

Originally Posted by Hugh R

It's usually a bell shaped think at the main to the house. You have a screw on top with a locknut. I think you screw it in to reduce pressure.

Back it out to reduce pressure. Turning it in will increase the spring pressure which requires more water pressure to close it.

They are usually located outside the house on the main line coming into the house but it could be anywhere. Some houses don't have them but they should. Fairly cheap, prolly not more than $25 or so and it can prevent an over-pressure leak.

[sammyg2]

Question: It is noisy all the time, when one certain faucet is open, when any faucet is open, with all faucets closed, etc?

With everything closed and no flow, there should not be any noise at all. If it's noisy and no faucets are open and no water flowing, you have leaky leaky.

[rfuerst911sc]

UPDATE- My son took the pressure gauge we purchased to the neighbors house and their pressure was 50 psi !!! My son called the water dept. and they were concerned about the 100 psi and sending someone out. I'm guessing the main water meter might have a regulator in it that might have gone bad. I appreciate all the advice given here and so does my son. Thanks guys.