Ok do Tony's test only slightly different.
Turn the main stopcock off, the inside one and open the kitchen tap.
When it's down to a constant dribble, valve the pumped hot and cold off. Best turn the electric to the pump off as well.
Does the dribble stop.
Turn the pumped supply back on does the dribble start again.
Turn the main stopcock off, the inside one and open the kitchen tap.
When it's down to a constant dribble, valve the pumped hot and cold off. Best turn the electric to the pump off as well.
Does the dribble stop.
Turn the pumped supply back on does the dribble start again.