31/01/12/ 10:20 hrs.Tony, Either Burner needs cleaning or flame failure device defective. with oven off get your head in there with a tourch and locate the probe that goes across the burner take note of position. if you have access to a blow lamp light oven normally then apply extra heat to probe with blow lamp,( not a lot 3-4 seconds) if burner goes to full gas then burner needs cleaning if burner stays low then FFD defective. Burner removal for cleaning fiddley, FFD replacement more so and is a gas carrying part. It is not a thermostat fault. Off line now while 1900 hrs 31/01/12
Colin West Yorkshire
January 2012