Gas fireplace heater temperature sensor (thermopile) Key benefits Reliable flame sensing and safety: Detects pilot flame and generates the millivolt signal needed to keep gas control valves open, restoring proper ignition and preventing nuisance shutoffs. Direct replacement compatibility: Designed to functionally match original thermopiles. Appearance may differ, but electrical and operational performance align with previous components for seamless integration. Durable, long-life construction: Sturdy body construction resists routine wear and maintains sensitivity and accuracy over time, reducing service calls and downtime. Stable performance: Produces a minimum operating voltage of 750 mV once up to temperature and can be brought up gradually to the required voltage during normal startup and operation. What it does and how it solves problems Restores reliable control: If a pilot-controlled fireplace, water heater, or fryer is failing to maintain valve operation or is shutting down unexpectedly, replacing the thermopile with this sensor restores the required millivolt output for consistent valve operation. Reduces guesswork at service time: Functional compatibility with common OEM parts means technicians can replace worn sensors without needing an exact visual match. Maintains measurement accuracy: Built to preserve sensitivity so temperature-to-voltage response remains consistent for accurate flame detection. Compatibility and performance notes Compatible devices: Commonly used in gas fireplaces, gas water heaters, and gas fryers that rely on a pilot thermopile for flame sensing and control. Pilot requirement: Typically installed together with a pilot assembly for effective operation and stable millivolt generation. Operating condition: Thermopile should be heated to at least 700 °C during startup; the unit then generates voltage that reaches a minimum of 750 mV and can be raised to the required operating voltage as the system stabilizes. Typical applications Home gas fireplace: Replace a degraded thermopile to stop repeated pilot shutdowns and restore consistent gas valve operation. Residential or light commercial gas water heater: Ensure reliable flame sensing for steady hot water delivery and safe valve control. Commercial or restaurant fryers with pilot systems: Maintain safe burner control and reduce interruptions caused by weak thermopile output. What to expect when replacing Functional fit: The replacement part may look different from the original but is engineered to match the electrical and operational characteristics required for proper function. Long service life: Robust construction helps the sensor withstand regular use while retaining sensitivity and accuracy. Technical reminder Minimum voltage: 750 mV minimum operating output. Minimum heating temperature: Thermopile should reach at least 700 °C during startup and be allowed to rise gradually to the desired operating voltage.