the overflow pipe is always dripping and when i turn my heating off the lights come on when it has cooled down and i have to fill the boiler up again with water for about 20 seconds
By overflow, I assume that you mean the outlet from the overpressure valve. What pressure you filling to?? should be about 1 bar, not over. THAT is when system is cold. If still leaking, the valve is faulty, replace.
