Could someone please help me. I have a glow worm boiler. The pilot light is on but when the central heating is put on constant the main burner does not fire up. Is this a simple problem to overcome?? Are there any airlocks?? All replies greatfully appreciated. Thanks in advance. ![Smile :) :)](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)