Just installed new high efficient toilet. Works great, but at rest I hear a constant water hammer noise that goes away onlt during flushing and refil. Any ideas?

Did you check the water level cut off valve to make sure it's properly set at the proper level. It may be set too high and the water keeps shutting off and on causing the hammer effect.

Put your hand on the fill valve inside the tank and tell me if it vibrates while you are hearing the noise? What brand toilet did you install and was the valve already in the tank when you bought it?

All good questions. You don't hear any hammer when you open and close the vanity cold water faucet do you? Bob's on to something. Noise is caused by vibration. Where the vibration's the strongest that's where I would start checking . Good luck, Tom

7-11 plumbing in cook and dupage counties Drain water to whole house turn main off open all faucets flush all toilet BUT first open laundry faucet Let all water hot and cold drain through there then turn off every thing you opened and turn water main back on then open one at a time every thing call me in the morning >Removed< Perry GOOD LUCK

"7-11 plumbing in cook and dupage counties " what does that mean? And what would your advice accomplish?

Ballengerb 1 I forgot to put ill. And the air chambers for fixtures could be filled with water so it's possible to be remedy if that's the case thank you perry

I'm still attempting to ascertain if this is a case where the air chambers need to be recharged.
I'm still waiting for a response fro my question.

You don't hear any hammer when you open and close the vanity cold water faucet do you? Let's see if I hear back. Regards. Tom

Perry you have to start reading what your typed and then make edits " I forgot to put ill" Still wondering about 7-11 Dupage. I doubt that this is a bad air chamber since it started when a new toilet was installed. We will never know if the OP fails to come back and answer us.

ballengerb1 I know but everyone is not perfect all the time.
Thanks perry

ballengerb1 you might need a license plumber sometimes call.
THANKS PERRY

I am not ragging on you Perry but we can't read what you wrote. Look at the bottom of each of your recent posts and you will see EDIT and QUOTE USER. Proof read what you type and then click EDIT if you see an error. Guess you aren't going to tell us about either sentence in question.

ballengerb1 Ihad put my phone number and I guess you are not suppose to .What else would you like to know. Where it said remove. I'm new at typing.Perry

Hi Perry,
Do you get a water hammer when you shut off any cold water faucet in the bathroom? Any place else? We instal air chambers on all lavatories and the kitchen sink to prevent water hammer. I'm trying to figure out if yours need to be recharged. Simply draining the system isn't going to do it. There's a set procedure that we use. Let me know, Tom