Im sure this problem has been posted a dozen times already, but here goes: The pilot light on my gas water heater wont stay lit. After manually re-lighting, the heater seem to cycle just fine. However, a couple of minutes after the main burner shuts off, I can hear a click in the controller and the pilot light goes out. I can re-light it no problem, but the same thing happens. Is the sensing thermocouple that sits next to the pilot light bad? The heater is over 20 yrs. old, and I dont know if its worth repairing as opposed to replacing. Thanks in advance for the help!