i have a potterton profile 60e that fires up and cicrculates but all of a sudden the boiler makes a terrible vibrating noise. which sounds like the solenoid? also the boiler stat does not appear to control the boiler except when you turn it back to 0 but the boiler seems to keep chugging away when the boiler stat is on.I have checked the f and e tank and there is water in the system any help would be greatfully recieved.