[HVAC1000]

When my dishwasher finishes filling and cuts off its water the pipes in the basement knock around and make a loud thump (I've heard it called water hammer). Will an expansion tank solve this noise? if so where in the water line should the tank be located? if not what will solve this problem?

 

[Ishmael]

If you have access to the pipes in the basement, the first (and cheaper) thing you could try is to properly secure the pipes to the framing. This will either cure the problem, or just transfer it to another section of piping that hasn't been secured yet.

 

[tylernt]

An expansion tank, if placed physically near the dishwasher, would help but there are better ways. As Ishmael says, first strap the pipes down. If these are copper pipes use copper clamps, if they are galvanized use steel clamps, if CPVC use plastic. If necessary, add chunks of 2x4 or even 1x wood to create blocking in joist bays etc for you to screw the clamps to.

If you still have an issue, you can add a water hammer arrester near the dishwasher. It's a miniature, less expensive, version of an expansion tank. Just tee it in as close to the dishwasher as possible.

 

[HVAC1000]

Alright guy thanks so much the pipes were just loose and needed to be secured