Q313A / 071515 750-Millivolt Gas Thermopile Generator (24")

High-Output Power Generation: Specifically designed to generate approximately 750 millivolts (0.75V) of DC electricity from the heat of a pilot flame, providing the necessary power to operate a self-powered gas valve without external electricity.
Aluminum-Jacketed Protection: The 24-inch lead wire is encased in a flexible aluminum jacket that provides superior heat resistance and shielding against mechanical abrasion inside the burner box.
Rapid Response Time: Engineered with high-sensitivity internal thermojunctions that reach full power output quickly after the pilot is lit, reducing the wait time to engage the main burner.
Standard 2-Wire Connector: Features a universal two-terminal spade connector compatible with most millivolt-controlled gas valves used in residential and commercial appliances.
High-Temperature Durability: The sensor tip is constructed from heat-stabilized alloys designed to withstand constant exposure to a 1500°F pilot flame without melting or degrading.

Primary Part Numbers: Q313A, 071515.
Cross-References: 60125501, 50332, 2103-512, 10332, 10332X, 332, 71515.
Manufacturer Equivalents: Honeywell Q313A, Robertshaw 1950-001, Johnson Controls K16系列.

This thermopile is a universal replacement for self-powered gas systems (no plug-in power required). Key applications include:

Gas Fireplaces & Log Sets: Compatible with many Heatilator, Majestic, Superior, Vermont Castings, and Monessen units utilizing a millivolt valve.
Commercial Foodservice: Fits various gas fryers and ovens from brands like Imperial, American Range, and Pitco that require a 750mV pilot generator.
Gas Water Heaters: Suitable for certain older high-output or commercial-grade water heaters.
Note: This is a 750 Millivolt generator. It is not a 30mV thermocouple. If your gas valve has a screw-in threaded connector, you likely need a thermocouple instead. This part has two push-on spade terminals.

Main Burner Won't Ignite: The pilot flame is lit and hitting the thermopile, but the main burner fails to turn on when the thermostat calls for heat.
Pilot Flame Goes Out: If the thermopile cannot generate enough millivolts to hold the safety magnet in the valve, the pilot will not stay lit after you release the knob.
Low Voltage Reading: When tested with a multimeter, the thermopile produces less than 325 millivolts (under load) or 600 millivolts (open circuit), indicating the internal sensor is failing.
Soot Build-up: Heavy carbon or soot on the thermopile tip can insulate it from the heat, leading to weak voltage output. If cleaning the tip does not restore function, replacement is necessary.
Damaged Lead Wire: The aluminum casing is melted, kinked, or the internal wires are exposed, which can cause a short circuit.

Safety First: CRITICAL: Turn off the gas supply to the appliance before removing the pilot assembly.
Clean the Pilot Orifice: PRO TIP: While the assembly is apart, use a piece of compressed air or a thin wire to clean the pilot burner. A weak or "lazy" pilot flame will not heat the new thermopile enough to generate the required voltage.
Proper Positioning: Ensure the top 1/2 to 2/3 of the thermopile tip is engulfed in the pilot flame. If the flame only touches the very tip, it will not reach full power.
Finger Tight Plus: When connecting the spade terminals to the gas valve, ensure they are snug. Loose connections add resistance, which can prevent a low-voltage millivolt system from operating.
Check the Thermostat: If the burner still doesn't light with a new thermopile, check the thermostat wiring. Because the system is self-powered, even a small amount of corrosion on the thermostat wires can stop the signal.

House - Water Heater Parts