632427R Nordyne Pressure Switch

Product Overview

632427R is an official Nordyne OEM −0.55″ WC SPST pressure switch for gas furnaces and HVAC systems. It detects the negative air pressure generated by the inducer motor before allowing ignition, ensuring safe combustion and system reliability.

Technical Specifications

• Switch type: SPST (Single Pole Single Throw)

• Activation threshold: −0.55″ Water Column (WC)

• Connection: 1/4″ barbed vacuum hose nipple

• Contact action: closes upon reaching vacuum setpoint (normally open)

Cross-Reference Part Numbers

This switch replaces multiple legacy Nordyne and Miller part numbers, simplifying inventory and stocking.

Compatibility

• Nordyne gas furnace models requiring a −0.55″ WC pressure switch

• Miller-branded units with equivalent combustion air switch requirements

• Verified fit in Nordyne KG6RA 09C-16B series furnaces during field installations

Always confirm compatibility with the appliance’s service manual or manufacturer.

Technician Notes

• Isolate electrical and gas power before servicing.

• Tag and photograph vacuum tubing routing for accurate reassembly.

• Replace with 1/4″ vacuum tubing rated for negative pressure (e.g., part B13-614).

• After installation, apply a heat call and verify the inducer runs and the switch closes at −0.55″ WC.

• Check for leaks around tubing connections and ensure reliable switch actuation.

• Test safety circuits and fault codes per the OEM service manual.

Additional Resources

• OEM wiring diagram and installation manual (PDF)

• Pressure switch vacuum tubing guide with fitting references

Pressure switch. NO, 0.55C. 1 hose nipple. Also referred to as a combustion air switch or draft proving switch. Switch closes when the combustion/booster motor runs creating a negative air pressure.

For replacement tubing, order part # B13-614.

Replaces 632212, 6322120, 632124, 6321240, 632385 & 632427.