In the last couple of days, it sounds like the meter is always spinning and the downstairs toilet(yes get me) there's a trickling noise to a pipe
Put a line of loo paper around the inside of the pan. If there's a trickle of water from the cistern, past the syphon then the paper will show it up.
If there's a cistern overflow pipe that goes outside , is the water level below the top.
Do you have a pressurised hot water cylinder?... which will have over pressure and over temp valves.
They can leak (or flow water as designed) you'd see it going through the tundish if applicable.
Put a line of loo paper around the inside of the pan. If there's a trickle of water from the cistern, past the syphon then the paper will show it up.
If there's a cistern overflow pipe that goes outside , is the water level below the top.
Do you have a pressurised hot water cylinder?... which will have over pressure and over temp valves.
They can leak (or flow water as designed) you'd see it going through the tundish if applicable.