I have had the problem sorted - the insulation had fell onto the burner so that was fixed and the insides were cleaned.
Since we had work done though, we seem to be using a hell of a lot of gas - we're on a pre-payment meter and are using £20 or more a week on gas. This is a great deal more...
My Baxi Solo boiler (WM40/4RS) is intermittently making strange noises... I thought it may be because of the high winds but since they have dropped, it's still doing it. The best way to describe the noise is as if you were blowing hard on the gas flame...I have absolutley no idea what it could...