Overflow pipe/hot water

[boyleastlikelyto]

Hi, thanks in advance for any help.

Over the last few weeks an overflow (the left facing from the roof area) has begun dripping at a steady rate. This appears to happen morning and night when the hot water switch has been on for about 60/80mins. The water coming out of the overflow is cold, but if I run a hot tap for a few minutes the overflow stops. If I dont do this it seems like a few litres comes out each time.

Any suggestions appreciated. Many thanks.

 

[bab]

The feed & expansion cistern thats feeding your cylinder has too high a water level so when cold there isn't enough cappacity for the expansion when you cylinder heats up Maybe ballvalve needs adjusting lower or a new ballvalve washer required or even a new ballvalve.