Pipes hammer/squealing while water is running

[traut27]

Water pressure in my home was at 120 psi. I replaced the existing PRV with a new one and my water pressure is currently 45 psi. Now when I run water I get a loud hammering/squealing noise from the pipes while the water is running but it doesn't happen all the time. The most consistent way to see the issue is when using the fridge dispenser it starts to do it once you almost fill a whole glass. Then it will stop as soon as you stop the dispenser. It occurred while using my washing machine as well. Other than that I've only noticed it once with my shower and once with a faucet over the span of a week. The noise itself is very loud and concerning but it stops as soon as the water is stopped.

 

[Reach4]

To work around this PRV noise generation, you could try raising the PRV pressure a bit... to maybe 55?

 

[Sponsor]

 

[Jadnashua]

Do you have an expansion tank in the system? If you do, have you checked to see if it is functioning properly? May not be related, but adding a PRV creates a closed system, and if you don't have an ET, once hot water is used and it expands when the cold is heated, the pressure will spike again. An old, failing PRV might allow that expanding water to flow backwards into the supply. A new one is trying very hard to prevent that, and some noises could occur as a result. The expanding water needs a place to go or it puts huge stresses on things.

 

[traut27]

To work around this PRV noise generation, you could try raising the PRV pressure a bit... to maybe 55?

I increased it to 55 and it no longer makes the noise while using my fridge dispenser or my kitchen sink but it still occurs sometimes while using my washing machine or my shower faucet.

 

[Reach4]

I increased it to 55 and it no longer makes the noise while using my fridge dispenser or my kitchen sink but it still occurs sometimes while using my washing machine or my shower faucet.

You could replace the PRV, perhaps with a different model. Or you could try working around the problem by raising the pressure to 65. Or 70 or 75. Remember to increase the air precharge on your thermal expansion tank accordingly.

A call to the maker of the new PRV might get you a replacement.