With this type of valve the brass stem is bent downwards carefully to adjust the water level.
Overflow pipe from tank in attic.
If its the toilet it will be directly connected to the white overflow pipe so should be easy to trace.
Looking for some advice.
I think you might be right about the tank on the landing.
The tank will either be your cold water header tank or the flow and expansion tank for the heating system and the valve is a type 1.
Set it very low but water is above the float.
The tank in the attic has been trickling out of the overflow for a few weeks now.
If not then u will still have a expansion tank in the attic with an overflow.
If the water in the tank or cistern fills up to a higher level than it should the excess water flows down the overflow pipe and runs outside rather than leaking into the room.
I have an open vented system with a hot water pump stuart turner monsoon twin 3 fitted.
An overflow pipe leads from a water storage tank or cistern inside your home to the outside.
For any roofing issues visit.
Tested it fine know it shuts off the feed that way.
Have already changed the valve and float in the attic.
If this leak is very recent then the ball valve needs a new washer as the tank is overfilling.
It could be that tank or it could be a toilet overflowing.
They re a vital part of your home s plumbing system.