Nordyne SPST Pressure Switch

The Nordyne SPST pressure switch (also called a furnace air pressure switch or draft pressure switch) is an OEM replacement control for Nordyne gas heating equipment. SPST stands for single-pole, single-throw. The switch opens or closes a single electrical circuit in response to pressure changes.

Key Features:

• Draft proving function: Senses negative pressure from the inducer motor. This confirms there is enough airflow and venting before the ignition sequence continues.
• Safety protection: Helps keep the furnace from firing when venting is inadequate. This protects the heat exchanger and supports safe operation.
• SPST circuit design: Simple open/close switching that is straightforward to wire.
• Factory-calibrated set point: Each part number in this line is calibrated to a specific water column (WC) pressure rating.
• OEM replacement: Made to match the original Nordyne control for dependable operation in residential heating systems.

A failing pressure switch is a common reason a furnace won't complete its startup cycle. Replacing it with the correct OEM switch can restore normal operation. Installation is usually simple, involving mounting screws, the vacuum hose connection and the electrical leads. It should be done by a qualified HVAC technician, following the unit's service manual.