Apologies if this is a common question, butI've tried searching the NG and found nothing, so here goes
My hot water header tank intermittently overflows causing fairly heavy dripping (which is battering the hanging basket, which is why I'm getting grief !)
It seems commonest on bright hot days, and it does not seem to be affected by the CH/HW being on or off.
on examining the header tank, the water level is very high (obviously !) but the ballcock is fine
what do I do before the Surfinias are battered to death and the in-laws are on the war path ?
Mike