baxi gf super gas fire on/off switch broken. help!?

I have a baxi gf super gas fire with baxi boiler at the back. The fire's on/off switch is broken. Where can I find a replacement? I can't afford to buy a new fire and the central heating costs a fortune. Help! I had thought that I would be able to disconnect fire and just place an electric fire in the hearth, but have found out that I can't do this.