I have recently moved into a house with a Glowworm Economy Plus 60B boiler. It was working fine for the first week but when the gas man came and turned the gas off at the mains the pilot light would not stay lit. I have changed the thermocouple and the problem is the same. Can anyone suggest what the problem is likely to be. Someone has said it may be the gas valve but it appears to be an expensive part to replace when there is no gaurantee it will fix the problem. If it is the gas valve, can they be repaired?? suggestions appreciated...