Mercury Minimization / Mercury-Containing Flame Sensors

Description: The metal flame sensor consists of a metal bulb and thin tube attached to a gas-control valve. The mercury is contained inside the tube and expands or contracts to open and shut the valve.

How to Identify: Several types of gas-fired appliances that have pilot lights, like ranges, ovens, clothes dryers, water heaters, furnaces, and space heaters use mercury-containing flame sensors. Some non-mercury flame sensors have been used in these appliances, but you should treat all sensors as if they contain mercury, unless you know for sure that they don't.

Alternative Devices: Electric flame sensors are mercury-free and have been used in some appliances.

How to Locate the Device: Most often, mercury thermostat probes are part of the safety valve that prevents gas from flowing when the pilot light is not lit. In this case, the bulb of the thermostat projects into or near the light. Mercury flame sensors are also present sometimes as part of the main temperature-controlling gas valve. In this operation, the sensor would be located in the air or water that is being heated, and not in direct contact with the flame. These are typically in older ovens, clothes dryers, water heaters, and space heaters.

Safe Removal: Remove the entire flame sensor unit from the appliance.

Safe Disposal:


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