Britich Gas Alarm

[luminaire]

that only seems to be a user manual not an engineers manual.

unfortunately i have heared that many companies are rather sensitive about thier engineers manuals being posted on the web.

I must admit I didn't look at it, it just said manual.
I have most manuals but not yours, so perhaps you should consider getting another panel instead. If you do make sure you know what each wire is for before you remove it. And put in a new battery too.