Wayne clarke
Hi mark It all depends on what you have in your house. A toilet as a overflow pipe you could diagnose by looking in the cistern if it is at a level where water is at the top of the pipe this will be grey/white change the filling valve. If you have a system boiler and cylinder then these also have header tanks in the loft usually, change the float valve if the water is at the point of the outlet to the overflow pipe. If it’s a combo boiler it could be your condensation pipe this will leak regular as the boiler is working, this is generally around half a cup of water every 10-30 minutes boiler depending. New regulations state 21.5mm pipe shouldn’t be externally as this could cause freezing in turn then back up and stops the boiler working. New regulations state 32mm pipe before it leaves the property. Hope this helps
