Furnace starts but shuts down quickly; control board flashes or displays E2 and the blower may run continuously.

Safety: Disconnect electrical power and shut off gas before servicing. Allow furnace to cool completely.

Diagnostic steps:

• Locate the supply air temperature sensor in the supply plenum above the heat exchanger on your Westinghouse furnace.
• Inspect the sensor body for discoloration or cracking from overheating.
• Check the sensor wiring for melted insulation or contact with the hot flue collector box.
• Unplug the sensor from the control board and measure resistance with a multimeter at room temperature. Compare to the manufacturer chart; replace if reading is open, shorted, or far out of range.
• Repair any damaged wiring and secure it away from hot surfaces using high-temperature wire ties.
• Reconnect everything, restore power, and clear the code by cycling power. Observe a full heat cycle.

Note: If the sensor and wiring are good but E2 remains, the IFC may need replacement by a professional.