Baxi gas fire will not light?

Hi,

I have a Baxi Bermuda inset boiler with a coal-effect gas fire. The boiler is fine, but the gas fire will not light.

Lighting should take place after around 20 seconds - you press a button at the side of the fire unit for around three seconds: a constant tone is heard while there is a ticking noise from somewhere inside the fire.

When it used to work, after around 15 seconds I could hear a sort of whooshing noise, as if gas was being pumped. It no longer does this and the fire does not light.

Is this something I can fix myself, or should I contact a CORGI engineer?

Many thanks.