I have replaced my thermocoupler 3 times in the last year?

The flame from the pilot light should ONLY JUST touch the top edge of the thermocouple. Also the flame should be blueish in colour, if yellow then the air inlet is blocked, needs cleaning out. This not variable as it is set, so the air holes should be cleaned. Gas pressure to the pilot light is also set and should NOT be tampered with. Usually if the thermocouple top has burst it shows too fierce a pilot light. Another fault might be the main burner flame being too fierce, burning the thermocouple, again this is set and should only changed by a gas competent person. DO NOT TRY TO DO THIS YOURSELF. Good luck.

Graham F....
January 2014