Toilet Refills when Water Elsewhere in House is turned off

[Sarah]

We live in a new house (1 year old, have lived there for 1 year) and within the past couple of months, our master bath toilet has been acting up. If we turn on the faucet to brush our teeth and then turn the faucet off, the toilet gives two quick refills. Same thing with the shower, washing machine, etc...any other water within the house...when it is turned off, the toilet refills. Doesn't happen every time, but often.

The plumber said our tank water level was too high and he adjusted it lower. This did not solve the problem. I had read that maybe it was a pressure problem. No one really seems to know what this could be.

If anyone has any ideas, I would really appreciate it! Thanks,

-Sarah

[Joseph Meehan]

I would suggest that it is likely the valve needs to be replaced.

[Joe Bobst]

Confirm this by comparing your present and last years water bills. HTH

Joe

[John Barry]

Your flush-valve may be leaking slightly, such that after tank level drops a bit, pressure-surge from other valve(s) closing cause fill-valve to open momentarily. Else, it's just pressure-surge trigering flow.

A little food-coloring in tank will give away leaking flush valve, which is easily replaced. Pressure-surge ("water-hammer") can be cured with air-filled expansion space in supply line, at appropriate spot. Could be simple, could be PITA.

HTH, John

[Sarah]

Thanks! I can do this. Just to clarify (I have zero experience in home repair), which 'valve' are you talking about and is this something I can do myself? Also, it's not as if the tank is leaking and refilling (I've seen that in a different house before)...I think the water is staying where it should be just fine...it's when water elsewhere is turned off....I've heard it's a 'pressure' problem and it's a 'vacuum' problem.

Thanks again for your advice!

-Sarah