I'M TRYING TO RELIGHT MY GLOW WORM SPACE SAVER MK2 CENTRAL HEATING BOILER. I HAVE FOLLOWED ALL THE INSTRUCTIONS BUT WHEN I RELEASE THE PILOT LIGHT BUTTON, THE PILOT LIGHT KEEPS GOING OUT. I HAVE DONE THIS ABOUT 200 TIMES BUT THE PILOT LIGHT STILL KEEPS GOING OUT. WHAT ELSE CAN I TRY?