Water hammer problems whole house.

[Bob123456]

Hi Everyone

I had a water filtration system installed by a professional company recently and am experiencing water hammer throughout the house.

It is most noticeable in my main floor powder room that has a new toilet.

After the toilet is flushed a random series of bangs and (water hammer) sounds come from the floor below.

I have also noticed noises when no water is in use late at night.

Since the system was installed I have had the plumbers install a PRV to drop the pressure from 80PSI to 60psi.

I have also installed a Souix Cheif water hammer arrestor on the toilet but it doesn’t work consistently.

Would the next step be...

Adding a large water hammer arrestor on the main cold water line after the filtration system ?

Adding a pressure tank to deal with the late night pipe noise (thermal expansion?)

Or is there another solution that would work?

The house is only 20 years old so the copper pipes are new but I believe that there probably aren’t any air chambers anywhere in the plumbing system.

Thanks for your help,

Bob.

 

[Jadnashua]

WHenever you add a PRV, you should automatically install an expansion tank, so first thing I'd do is add one of them and see what results.

FWIW, the old school air chambers tend to fill up with water after a couple of months and become useless...the air trapped in there gets absorbed by the water as it passes by at the junction and water slowly fills it up.

Without an ET, the pressure will rise until the weakest link leaks. If the PRV you bought has an overpressure valve in it, that could be opening when the pressure reaches above your supply. A very common valve that doesn't like high pressure is a toilet fill valve. SOmething is leaking to relieve the pressure, otherwise, you'd be seeing the T&P valve on the water heater open. Expanding water will quickly spike the pressure high enough to open that valve when it reaches 150-psi unless something else leaks first.

 

[Sponsor]

 

[Bob123456]

WHenever you add a PRV, you should automatically install an expansion tank, so first thing I'd do is add one of them and see what results.

FWIW, the old school air chambers tend to fill up with water after a couple of months and become useless...the air trapped in there gets absorbed by the water as it passes by at the junction and water slowly fills it up.

Without an ET, the pressure will rise until the weakest link leaks. If the PRV you bought has an overpressure valve in it, that could be opening when the pressure reaches above your supply. A very common valve that doesn't like high pressure is a toilet fill valve. SOmething is leaking to relieve the pressure, otherwise, you'd be seeing the T&P valve on the water heater open. Expanding water will quickly spike the pressure high enough to open that valve when it reaches 150-psi unless something else leaks first.

Ok thank you very much, I will get an expansion tank installed and see how that goes.

I think there is a slow leak on one of the cold water lines heading to the upstairs bathroom.

 

[Fitter30]

Try draining the house down. Turn water heater off shut off main water open all valves leave them open for hour or two then refill house house. Air cushions that are piped in the walls might be full of water not air.

 

[Bob123456]

Try draining the house down. Turn water heater off shut off main water open all valves leave them open for hour or two then refill house house. Air cushions that are piped in the walls might be full of water not air.

Tried this several times doesn’t work.

 

[Jadnashua]

The use of 'air cushions' in a supply system was shown to be a very short-term solution to water hammer ages ago. They tend to quickly get their air absorbed into the passing water and fill up. And, like a straw with your finger over the end, they don't drain well when you shut off the water, either.

IF you need a water hammer arrestor, you should consider an engineered one. They do fail eventually when their seal dies, but work just fine for far longer than an air cushion.