Has me and my neighbor stumped. The pilot light stays on and brings up the burner when the thermostat calls for it. Once the heating cycle completes, both the burner and the pilot extinguish. I have replaced the thermocouple assembly (includes pilot feed and striker element) and the flow control valve. The symptoms have not changed. The tank is only five years old and not ready to buy a new one. Saving up for a higher end hybrid, maybe. Any help, any ideas?