We have installed a new toilet it functioned perfectly for six weeks then the water will run every five minutes for a few seconds? We have replaced the flapper we have tightened the bolt inside the tank and tightened the spigot between the tank and bowl. And it is still coming on every five to ten minutes will top itself up? You can see a water flow into toilet bowl a steady trickle? Please advise? It is a one piece toilet and bowl

I am not sure what type of toilet you have but the way you say the problem is with your flush valve seat where the flapper valve set, get some steel wool and clean the seat, good luck.

John