Plumbing question

[abunaitoo]

Are there any plumbers out there????
I'm not sure if I have something wrong or not, but I want to check with someone who might know.
After I flush the toilet, when the tank fills up and the water shuts off, I hear what sounds like the water pipe gonging. Kind of like something hitting the pipe with a wooden stick.
It seems like it's getting louder.
Any ideas/suggestions?????

[Glen Miyashiro]

Re: Plumbing question

Sounds like "water hammer".

[matapule]

Re: Plumbing question

It is called water hammer. It is caused by excessive water pressure. In order to eliminate it, you will need a pressure reducing valve.

[Nords]

Re: Plumbing question

Are there any plumbers out there????
I'm not sure if I have something wrong or not, but I want to check with someone who might know.
After I flush the toilet, when the tank fills up and the water shuts off, I hear what sounds like the water pipe gonging. Kind of like something hitting the pipe with a wooden stick.
It seems like it's getting louder.
Any ideas/suggestions?????

Water hammer indeed.

One cause could be the fill valve getting old and beginning to shut off abruptly, sending a pressure surge back through the piping that's rattling it. So the homeowner's cheapest/easiest option might be a new tank fill valve that gradually shuts off without causing water hammer.

Another issue might be the piping not properly secured behind the toilet wall. The water hammer rattles loose copper pipe and it bangs into things. Not easily fixed unless you can get into the wall to clamp the piping to a stud, and it doesn't eliminate the cause of the water hammer. Of course more modern homes have avoided this problem by using mostly plastic piping.

If your plumbing has an old water-hammer suppressor, over the years their air space can fill up with water and start the hammering. Some have fittings to recreate their air bubble, others need to have the entire piping drained. Generally not worth the effort but that's one way the water hammer begins to happen and gets louder.

[cynsaligia]

Re: Plumbing question

if you decide you need a plumber, call steve at state wide plumbing. he's been in the biz for years (having learned it from his now-deceased father) and comes strongly recommended by the guys who are in charge of hiring contractors like plumbers etc for the organization i work at.

[abunaitoo]

Re: Plumbing question

Thanks for the help.
Two toilets in the house. I only noticed it what one of the toilets is flushed. I'll check better with the other toilet.
Traced the noise to the back of the house, not near the toilet. Nothing back there but an outside water pipe. Probable a loose pipe clamp.
Older house, so I'll have to get into the crawl space in the roof.
Only reason I'm wondering about this is because the sound seems to be louder than I remembered it before.