overflow pipe

[wilkonumber1]

hello my overflow keeps running cold water comes out but when you flush the upstairs toilet it stops for a few hours
and also when i flush the toilet the pipes make a loud rumbling noise
thanks

[ianmunt]

Sounds like you either need to lower the header tank level(by carefully bending down the ballcock arm,but more likely the washer needs replacing.When you flush the tank level drops,so overflow stops.The tank gradually fills up to overflow level again.Unsure about the rumbles could be air in the pipe?

[wilkonumber1]

thanks for your help