My Moffat 500 TC cooker will only stay on with a small flame and does not fire up to reach the temperatures required. How do I fix this please?

Em, September 2007

You need a new flame supervision device,often referred to as an FSD,or FFD(Flame Failure Device),a very common fault.Cooker lights via a weep valve then as FSD heats up it operates a bellows allowing main gas valve to open.
If FSD is broken this doesnt happen hence the low flame.Expect to pay about £90 fitted,depending on model,takes about 20 minutes.

GRAEME SMITH, September 2007