RUSFOL Furnace Flame Sensor Replacement for Rheem Package Included： 3 X Furnace Flame Sensor Install Process: 1. To avoid danger, it is very important to shut off the power to your furnace (or any other appliance), prior to making any repairs. There will usually be a light switch (toggle switch) on or near your furnace. If this switch is not present, furnaces have a dedicated breaker; locate your furnace breaker and shut your unit down. 2. Remove the Sensor. Find the broken sensor. The sensor is easily accessible and typically mounted by one 1/4” hex head screw. Upon removing this screw, the sensor will slide out so that you can easily clean it. Carefully remove the sensor; 3. Remove one sensor and replace it with our new sensor. 4. Simply reconnect the wire if you’ve taken it off, remount the sensor to the burner assembly using the 1/4” screw, replace the door(s) on the unit, and turn the power back on. 5. Check Your Results. If the unit takes a few extra seconds to start up or the fan immediately kicks on and runs for a bit, this is normal. Shutting down the power to the unit can cause it to reset and run through a short series of checks before trying to fire again. Once this check is complete, the unit should begin to operate by command of the thermostat. Make sure the unit re-fires and runs properly until the thermostat is satisfied, at least once before being confident your problem is solved. NOTE: Turning off the thermostat does not shut down the power to your unit. Also, there are many different types of furnaces and appliances; if your gas valve is not electrically controlled, you will need to shut off the gas to the unit as well. Should you be confused about any of the information provided here, because it does not match with what you see on your unit, STOP! Call an HVAC professional in your area, in order to complete the repair on your unit.