A toilet runs intermittently but seems to start running most often after the shower is used in a nearby bathroom (or for no apparent reason or some time after the last use). Flushing the toilet normally stops the running. The water co. alerted us to a leak (900 gallons in 9 hours) when we were out of town. We think the running toilet was the culprit as keeping it turned off when all the water to the home was turned back on showed just normal usage. Until a plumber could come out we kept the water to that toilet turned off. The plumber made some adjustments to the fill valve and flappers and called it fixed. The running started again a few days later. Plumber came back to make some adjustments; problem still occuring and now flushing the toilet won't always stop the running so we've kept the water to it turned off. We told the plummer that the running seemed to be tied to other water usage but he did not think that was the case. So we still have a problem and I need some help determining the cause.
I've read a lot of the forum queries and think we might have a pressure problem.
Several years ago we had a flood from a (different) toilet. It happened when the washing machine and dishwasher were running and someone was taking a shower. We thought it was a clogged line but now I am not so sure. The flood waters were clear and not brown or yellow or with any solid waste. We replaced all 3 of the toilets in our home in the years follwing the flood so they are all less than 5 years old.
And also, when the water was turned off to the problem toilet, the toilet in another bathroom started running. Flushing that toilet stopped it.
I'm concerned the problem is not the toilet but the plumbing system. Any ideas?