How to Clean a Furnace Pressure Switch

A gas furnace pressure switch's function is to maintain the correct pressure inside the heater. Once the pressure reaches certain levels, the heater will turn on or off. If the pressure switch is stuck, it may not be able to turn the heater on or off. Cleaning the pressure switch may bring it back to life. If you notice the pressure switch doesn't perform properly after a cleaning, replace it immediately.

Things You'll Need

• Screwdriver
• Compressed air
• Soft brush

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Instructions

1. • 1

     Shut off the gas supply leading to the heater. Turn the gas valve so it is perpendicular to the pipe. Shut off the electricity to the heater at the circuit breaker.

   • 2

     Remove the screws from the heater cover. Pull the cover off the unit.

   • 3

     Locate the pressure switch. Remove the screw holding it in place.

   • 4

     Pull the pressure switch tube from the switch. Blow out the tube with a can of condensed air. Clean out the inner fins of the pressure switch using a soft brush.