I have a 20 year old house. For the past little while, I have noticed knocking in my second floor bathroom. This room is the furthest form the hot water and the water main. Since I have air chambers, I figured the air diluted in the water with time. I drained my pipes twice by closing the water main and opening all the taps in the house. I could hear the air being sucked in from that bathroom drain. It still knocks.
I have a toilet, shower and sink in that bath room. The knocking is caused by the hot and the cold water.

Help!

 

Hi.

Where are you hammer arrestors installed. ( Air chambers )

One on the hot and cold under the sink for that bath should take care of it. But water hammer can be tricky sometimes.

These are the best IMO. Its all I usually use.

0269503 - Watts 0269503 - 150A, 1/2" Water Hammer Arrestor

Chart to help with install.
http://s3.pexsupply.com/manuals/1249...stallation.pdf

Specs
http://s3.pexsupply.com/manuals/1249...ifications.pdf

Mike NJ

 

Hello Mike

When they built the house, I noticed that every water pipe going to a tap had a tee with a 6 inch pipe capped at the end.

Mike (Montreal)

 

Those devices were used because they are cheap. Since they are dead-ended, it's difficult to restore the air charge.

 

The piping is in my wall and would need to take out the shower to get the pipes. I have easy access to the piping in my basement which is about 10' away from the facets. Do you think if I installed the hammer arrestors in my basement this could resolve my issue?

Regards,

Mike (Montreal)

 

If you install A hot and cold arrestor under the sink in that bathroom, it should solve the problem for the whole bath. Possibly they will work in the basement too. I never tried it. I always installed as close to the bath that I could. Which would ne under the sink so they are not an eyesore.

You need to remove the valves under the sink and add a tee. 1/2 cc x 1/2 cc x 1/2 threaded.

Will they work? I dont know. They are rated up to water velocity of 10 fps.

Possibly you have another issue like high water pressure. If you have a PRV in the home it could be faulty. Your pressure in the home should be no higher then 80 psi.

Have you checked this?

Mike NJ

 

That's a great idea. I kept thinking I have to put this in the wall. I think I need a vacation. My water pressure historically has always been around 75-80 PSI in my old house. In this home, I don't know. I don't have any gauge to test this. I'll work on that.

Thanks for the help. It's greatly appreciated.

Mike

 

Possibly - try it......................