Rang around and found someone to service - £40 (cleaning, no parts needed) and it's all working fine now. Thanks for the advice on here, it's been really useful.
Hi - anu help you can offer much appreciated. Wall mounted Glowworm in garage, 7 years old, no problems to date, no recent work done. Yesterday no hot water or heating, had a look and it\\\'s sparking pretty much every second or so, there\\\'s a small blue flame in the tiny window on the front...