I have a Servowarm Elite 50 gas boiler to a pumped hot water and C/H system. About 3 weeks ago the pump became noisy and sounded as if it was running 'dry'. I discovered that a previous 'plumber' had turned off the supply to the header tank and not reopened it. The supply was turned on and all seemed fine. 2 days ago the boiler started to make a different noise and would only stay lit for about 10 secs. I have changed the pump in case that was the problem and bled the system as far as I am able. ( there does not appear to be any bleeds except on the radiators). The boiler now stays lit and water is being pumped round the system. The only problem is that the noise is still there. It is coming from an item on the PCB. A small blue 'cube'. It sounds as if it is clicking rapidly and loudly.
Can anyone help as to problem and solution.
Can anyone help as to problem and solution.