Toilet refils ONLY when sink turns on

[kimbo]

Hi, long story here but to give background I must ramble-sorry. We had to replace all the insides (don't know technical term) in the back of the toilet because it kept running. When that didn't work we again bought another new kit (thinking we broke it) Now it will flush but not fill back up until you turn the sink/shower on. And even then sometimes it will still run through the overflow pipe. Since everything has been replaced twice I assume it's another issue. Also our second bathroom all of the sudden needed new fixtures and only sometimes fills back up, but on it's own, no sink needed. This has been ongoing for weeks now and just yesterday our hot water heater's pressure relief valve is leaking. About a month ago we replace some sprinkler valves outside, shutting off all the water while doing so, could this have caused the pressure to somehow flip out and cause these problems. Things I've tried to fix ....

-TOILETS:
*3 toilet kits
*turned main water lines off and ran all water to get air out and then back on
*turning pressure down thinking it's too high

-HOT WATER HEATER:
*turned main water pressure down
*opened valve to purge any pressure

Do I need a plumber? Please help
Thank you!

[Caduceus]

A few questions first. How did you turn down the pressure? How did you read the pressure to check it and turn it down? Do you have a thermal expansion tank on your water system?

You should be turning the pressure down at your pressure regulator. Closing a main valve partially will not change your water pressure, but will only reduce volume.
A gauge is available at stores that screws onto a hose connection. Check the pressure with no water running in the house.

[kimbo]

Oh, no didn't use a pressure regulator...just moved the knob to halfway, which like you said only reduced the volume from all faucets. Someone showed me the pressure regulator outside connected to the main, maybe it needs replaced? Looks old...and not sure about thermal expansion tank? How can I tell? Just seems odd that replacing a sprinkler pipe caused this, if in fact it did...

And thanks so much for your help!

[kimbo]

Caduceas thanks again for the response....54 views and 1 reply, maybe this isn't a common problem but I thought I'd post my solution for others just in case.

The plumber simply changed my old pressure regulator valve (outside, connected to main) He says most homes run about 100psi and mine was 170psi. 10 minutes later....water heater no longer leaks and toilet flushes normally again YAY!

[havasu]

Wow, 170 PSI is dangerous. I even believe 100 PSI is still a bit high.

[kimbo]

I'm sorry, I should've said that he (plumber) meant homes with a high psi in his experience have been about 100 (mine at 170)....he set mine to 80psi, I should have stated that part I do feel like the pressure in the sinks are too low though...or maybe I just got use to it being too high.