The upsairs toilet will run as soon as you use any water in the house such as, turn on the tap or shower. It's a swedish push button toilet and doesn't have a normal bullcock, We have tried adjusting it but it still runs water into the pan as soon as you turn a tap on.

The upsairs toilet will run as soon as you use any water in the house
Take the lid off your toilets and check the tank level. It should be 1/2" under the white overflow tube.
Now, with the lid still off turn the cold water of and on. Did you see the float ball bounce when you did this? Let me know, Tom