City Water Pressure Causing Hammering

[Charles419]

We've lived in our home for several years, no hammering. Within the week, hammering is occurring without any household valve or solenoid being activated. I confirmed this at the water meter ( a new digital/wireless unit for the city). I've watched the meter to see if there is a slow leak or other and my wife yelled "it's hammering!".

There is no rhyme or reason to start the hammering (leaking toilet lets say and when tank is refilled, hammering starts, or washing machine).

Pressure at the service to the home is 65-70 psi. When the hammering occurs, that gauge varies by +/- 10 psi - easily.

I've had this create failures and repairs at the water heater already.

Any ideas or thoughts as to the cause and a solution ?



Chuck

 

[Dj2]

Do you have a Pressure Reducing Valve (usually located around where your water main comes into the building).

 

[Sponsor]

 

[Jadnashua]

When they did work on the meter, they may have also added a check valve. Many places are doing that since it protects the supply from some fault in the home that might flow back into the system and pollute the water, potentially poisoning you and your neighbors! If they did that, you may need an expansion tank, or if you have one, it may be underinflated or defective. When this happens, does the WH discharge anything from the T&P safety valve? Do the hammers occur after any hot water use that might trigger the WH to turn on? Heating water causes it to expand, and if there's a check valve in the system, it will stress things, and leak out at the weakest link. That pressure can cause things to move around, then back again, after the pressure is released.

 

[Reach4]

When the hammering occurs, that gauge varies by +/- 10 psi - easily.

Would those variations be short duration -- less than a second for an up and a down gauge movement? If so, I would suspect you are near a pumping station, and you should get the water company/department involved.