hi all, i own a highflow 400 and the parts changed on it are diverter valve, air pressure switch, fan assembly, gas valve. my heating and water worked perfect for a week but now when the heating or water is on with the lights on the boiler tends to fire up so the flames on but then it trys to fire up again and then flames on. carrys on with this process i have no clue at all now what it could be any help would be appreciated thanks
