check the s trap at the bottom of boiler ..its simple to remove via 2 screws/ it can get blocked and water builds up inside the boiler . this can cause the boiler to bang and rattle . drain and clean s trap ..if water is present then when emptied. the boiler should run normally .its surprising how much water can collect before the boiler will fail ..usually runs noisey first .Can be very noisey and sometimes the fan runs slow and then picks up speed
error code L8 flashing . indicates gas flame problem ...Again this fault can be caused by water unable to drain away .
septimus
September 2008