Hi, When my boiler first fires up in the early morning the header tank overflows. After a while it does stop but I cannot understand why. One clue may be that a few weeks ago I had to drain diwn the system to fit a new valve to a towel rail and this problem has only started since then. Is there a connection. (no pun intended). Gotabelt
Hi gotabelt Most likely the water level in the header tank is too high, the expansion when heated is considerable. It should only be about 1/3 full when cold. It may also be that the ball valve is 'letting by' not fully shutting off. Let's know how you get on, there may be other causes, so the simple one first!
Hi Proptech, got it sorted. It was extreemly difficult. When I checked it was not the header tank that was overflowing but the cold water tank. The chipboard cover of the tank had started to de-laminate and had partially collapsed onto the ball float. with obvious results. Solution: made up a new cover (NOT chipwood) and fitted. Took the opporunity to turn the washer over in ball valve. Took all of 15 minutes. P