Allied Air 14a45 Pressure Switch 2 Stage

Product DescriptionThe ALLIED AIR 14a45 is a two-stage pressure switch designed for use in gas furnace systems where draft pressure must be verified before ignition can proceed. The switch monitors two set points, 0.50 inches and 0.90 inches water column (WC), providing the control board with a safety signal that confirms proper inducer operation at both heating stages. Licensed HVAC technicians install this component as part of routine furnace maintenance or when diagnosing inducer-related lockout faults. Its dual-stage design makes it appropriate for two-stage gas furnace applications where staged firing requires separate pressure verification.This pressure switch is intended for residential gas furnace installations equipped with two-stage burner control. It operates in tandem with the furnace control board and inducer motor assembly, confirming adequate negative pressure at each firing stage before allowing the ignition sequence to continue. Typical applications include forced-air heating systems where proper venting and combustion air verification are required at low-fire and high-fire conditions.Key FeaturesDual set-point design monitors both 0.50 inches WC and 0.90 inches WC pressure thresholdsTwo-stage operation supports low-fire and high-fire furnace control sequencesFunctions as a safety interlock to confirm inducer motor performance before ignitionOEM-style replacement form factor for straightforward swap-out serviceCompatibilityDesigned as an OEM-style replacement pressure switch for two-stage residential gas furnace systems requiring 0.50 inches and 0.90 inches WC set points.Installation NotesInstallation should be performed by a licensed HVAC technician in accordance with applicable mechanical codes and the furnace manufacturers service documentation. Always shut off power to the furnace at the disconnect and allow the inducer to come to a full stop before disconnecting pressure tubing or electrical connectors. Inspect the rubber hose connections for cracks or blockages, as a compromised hose will cause nuisance trips regardless of switch condition. Verify inducer performance and vent system integrity as part of any pressure switch replacement procedure.Technical SpecificationsPressure Set Points: 0.50 inches WC and 0.90 inches WCStages: 2UPC: 66255148810Standard InformationBrand: ALLIED AIRManufacturer Part Number: 14a45