Goodman 11112501 Pressure Switch for Goodman, Amana, and Janitrol Furnaces -- 0.33" WC

Direct Replacement, Correct Pressure Rating

A pressure switch that is out of calibration or has failed will typically cause a furnace to lock out on a fault code related to the inducer circuit. The 11112501 is rated at exactly 0.33" WC -- matching the factory specification for the furnaces it serves. Installing a switch with the wrong setpoint can cause nuisance lockouts or, worse, allow the furnace to operate without confirming adequate venting.

This part is also cross-referenced and sold under the NBK Parts number 20247, making it easier to verify compatibility when sourcing through multiple suppliers.

How a Furnace Pressure Switch Works

When the furnace call for heat begins, the draft inducer motor starts and creates a negative pressure in the flue system. The pressure switch -- a diaphragm-based device -- detects that negative pressure through a hose connected to the inducer housing. Once the pressure drops to the rated setpoint (here, -0.33" WC), the switch closes its contacts and signals the control board that safe venting is occurring. Only then does the sequence advance to ignition.

A failed or weakened diaphragm, a cracked pressure hose, or a blocked condensate drain can all cause the switch to behave as if there is insufficient draft -- resulting in a no-heat lockout. Replacing the switch is the correct first step after ruling out blocked flue pipes and a clogged drain.

Installation Notes

The 11112501 is a plug-and-play replacement for the original switch. Installation typically involves:

• Disconnecting power to the furnace at the breaker
• Removing the two wire leads from the old switch terminals (photograph wiring first)
• Disconnecting the rubber pressure hose from the switch port
• Unsnapping or unscrewing the old switch from its mounting bracket
• Installing the new switch, reconnecting the hose and wire leads
• Restoring power and running a test call for heat to verify normal sequence

Pressure Switch Specifications

Compatibility

Part Identification

What Is Included