When I turn on the room thermostat the main heating burner comes on for about 30 seconds then cuts out leaving a small flame if I push in the pilot light button the main burner comes on for about another 30 seconds then cuts out again

David Wilson, February 2008

Had this problem before. Required a new control system that sorted the problem. Try www.keeptheheaton.com for all spares.
Check the Johnson & Starley website for the part numbers and diagram, and order the parts from keeptheheaton.
All parts are genuine J&S with next day delivery.

jon seed, February 2008