DRIPPING OVERFLOW

[SWOLLENGLAND]

Recently isolated some of my CH system and fully drained the hot and cold water systems and now one of the header tank over flows is dripping (right onto conservatory roof like a drum!!) whats likey to be the reason for it to have started just after I had done the work I needed to do? and which one will it be the water tank or the CH tank ,not had time to get in the loft to check it out.Could it be as simple as I have opened up the stop tap too high when I put the cold water back on ?

CH etc running fine and doesnt appear to be any air in them.

 

[BoxBasher]

Recently isolated some of my CH system and fully drained the hot and cold water systems and now one of the header tank over flows is dripping (right onto conservatory roof like a drum!!) whats likey to be the reason for it to have started just after I had done the work I needed to do? and which one will it be the water tank or the CH tank ,not had time to get in the loft to check it out.Could it be as simple as I have opened up the stop tap too high when I put the cold water back on ?

CH etc running fine and doesnt appear to be any air in them.

Check the ballvalves on the tanks. They should automatically shut off when the water reaches a level. The arms may have got stuck in the open position or a the washer may have broken up/perished.