pilot light not working correctly?

Whatever it is it's a gas safe engineers job.

First check the flue outlet is not blocked or restricted in any way. If clear call a gas safe engineer (formerly Corgi).
UK new gas regs governs repairs replacements on all types of gas appliances. Too many accidents have occured with self repairs not done properly which is why they re-wrote the rule book. Cost around £40-50 plus parts( if any ) and all appliances are tested and a certificate given.

Bob
August 2011