strange water pressure problem

[ckd]

Hi:

Strange problems here...

First, I noticed that if I ran a sink then shut it off, the toilet in the same room would immediately run. I recently had all of the toilets (3) in the house replaced so I called the plumber who installed them and he sent a guy out. He took off the tank lid, ran and shut off the sink, and noticed that the tank water would ripple a little and the float would bob - causing the toilet to run for a few seconds. After poking around a little, he noticed that the water shutoff valve for the toilet wasn't working and blamed the problem on that. That made sense when he said it but doesn't really make sense to me now.

Second, a new refrigerator with a water line has been making an intermittant rattling sound. We finally discovered that if we run the kitchen sink then shut it off the fridge makes a small rattle. If we flush the problematic toilet, after it fills there is a pretty severe rattle in the fridge. We're guessing the water line tubing (flexible type) is being jerked around due to some pressure issue.

More info:

- Flushing a different toilet in the house has no effect on the fridge.

- I bought this house in January and all of the toilets had problems and they were all replaced. The problematic toilet was a major job - something about the toilet plumbing being off-set and out of spec. The floor had to be dug up and the new toilet positioned correctly.

- This house also had a cracked foundation and was sinking about 1.5". After the foundation was corrected with piers the plumbing passed a static pressure test.

That's about all I know. I'm especially concerned with potential backflow problems but any comments or insights about any of this appreciated.

Thanks!

[Joseph Meehan]

My guess is the supply/water lines in your home are marginal. Not to say defective, but marginal. You did not say what kind of supply you have (well vs. city) but if it is well, you may need a pressure tank, or you may need to dry out the one you have. These things just amplify the normal small increase in pressure that occurs when you turn off any water. The water has been traveling down the pipe and when it no longer has anywhere to go it causes a momentary increase in pressure.

That increase in pressure can cause the type of valve in a toilet to run a little and also can cause any supply line not properly secured to move a little. It is much the same as water hammer which can cause a bang when you turn off the water.

If this is only one sink that causes the problem, it may be just water hammer and you may need some arresters to stop it or the ones you have may be the older type and need to be drained. You can try this by shutting off the water supply and then opening all the supplies in the home, especially the low ones. (turn off the water heater first to prevent any possible damage there.

Good luck.

[Speedy Jim]

Change the ballcock (fill valve) in the offending toilet. Maybe even use a different brand. Changes in water pressure (such as by closing a faucet) should have zero effect on the toilet.

This toilet may also be responsible for the resonance which is occurring at the frig line.

Jim

[Don Young]