Hi All,

I have an issue with my pipes. Every time I flush the upstairs master bathroom toilet, there is pipe rattling/vibrating/hammering under the same bathroom's sinks. The noise ONLY occurs after the toilet has been flushed.

Any ideas would be appreciated. I have fixed a water hammer issue before and I feel like this is something different.

Here are some additional details:

- Brand new Toto and Kohler toilets throughout the house. All fill valves and shut off valves are also new.
- House is 17 years old. A three level townhouse with 3.5 baths. The problem is only occurring at the top level of the townhouse which is farthest away from pump/heater.
- Problem has been happening for over 10 months so it is not related to outside temperature.
- I have tried draining all the pipes in our house and I have tried running hot water for a long period of time through the sinks and tub at the top level. Neither have worked.

Thanks,
Nick

shut the valve under the toilet and flush.. what happens?

You need to find out where the pipes are not secured to the backing inside the wall and repair it. These sounds are normally associated with a piping system that was installed without proper strapping and insulation to prevent this. It is possible that everything is strapped and insulated but they missed one outlet. Also water hammer can be caused by quick closing valves such as a toilet ball cock, valves in your washing machine and dish washer and other valves. some times a water hammer preventor that you purchase from Home Depot can alleviate the situation. Good luck.

Hi packy,

I turned off the shut off valve and flushed. The rattling still occurs under my sink.

Thanks,
Nick

Hi Loren,

The pipes that rattle are not behind any walls. The pipes that rattle are directly under the sink.

Thanks,
Nick

that's a strange one ?? i was thinking the fill valve in the toilet had a loose washer and was vibrating. but we have ruled that out.
now, since the toilet is what is affecting things then we SHOULD be able to rule out any hot pipe related issues.
next, turn off the cold supply under the sink and flush the toilet.

Hi Packy,

I turned off the cold water valve under the sink and flushed the toilet. The pipes under the sink still rattled. I then repeated these same steps with the hot water valve. Same problem.

Thanks,
Nick

now, i hope you are proud of yourself.. you have stumped me.. hahaha just kidding, but i am stumped???