Selgas
Sure sounds like you have one of two things faulty there my friend, firstly I would suspect the thermocouple lead itself as being on it’s way out (failing), secondly it could be the main Unitrol valve ECO device that has failed, however if the latter is the case this fault is usally identified by the main burner lighting up as normal once the pilot is relight then once the water temperture as reached the set temperature it shuts off the main burner and also trips the safety device and shuts down the pilot as well, which will not relight until the temperaure of the water has dropped considerably below that of the set temperature. You may also wish to check the actual pilot burner is in fact playing directly onto the thermocouple lead – if not the thermocouple lead will not heat sufficently to operate the safety valve properly.
