A direct-replacement air pressure switch engineered for Trane and American Standard gas furnaces. This switch monitors inducer motor operation to confirm proper draft and vacuum before allowing the furnace control board to continue the ignition sequence -- keeping your heating system safe and reliable.
The air pressure switch is one of the most critical safety components in a gas furnace. It verifies that the inducer motor is spinning at the correct RPM and generating sufficient negative pressure (vacuum) in the flue system before the control board allows gas flow and ignition to proceed. A failed or out-of-spec switch can cause nuisance lockouts, no-heat calls, or -- if a faulty switch sticks closed -- an unsafe operating condition.
The Trane SWT2293 is a factory-specification replacement rated at 0.50" WC nominal, with open and close set points matched exactly to the original Trane and American Standard furnace designs that call for this switch. It replaces several legacy Trane part numbers and is also sold under the NBK Parts catalog number 20597.
Opens at 0.55" WC, closes at 0.65" WC -- matched to OEM specs for compatible Trane and American Standard furnaces.
Replaces SWT2293, SWT02293, and C341750P01. Plug-and-play swap with no wiring or plumbing modifications required.
Manufactured domestically to OEM quality standards for reliable, long-service performance in residential and light-commercial gas furnaces.
Monitors the vacuum created by the draft inducer motor. Prevents gas valve energization if proper draft is not confirmed -- a key furnace safety interlock.
When the thermostat calls for heat, the furnace control board first energizes the draft inducer motor. As the inducer spins up, it creates a negative pressure (vacuum) in the heat exchanger and flue assembly. The air pressure switch -- connected to this pressure zone via a rubber hose -- senses when the vacuum reaches the switch's closing set point (0.65" WC on this unit). Once closed, the switch signals the control board that safe draft conditions exist, and the ignition sequence continues.
If the inducer is weak, the flue is blocked, or the pressure hose is cracked or disconnected, the switch will not close and the furnace will lock out on a pressure switch fault code. This is the switch working correctly as a safety device. Before replacing a pressure switch, always inspect the rubber sensing hose and the inducer motor for signs of wear or blockage.