OEM Carrier SPST High-Fire Pressure Switch HK06WC091 for Model PG8JAA042090AAJA

This OEM pressure switch is the factory-specified replacement for the Carrier PG8JAA042090AAJA gas furnace. The pressure switch is a critical safety device that monitors the negative pressure (vacuum) created by the draft inducer motor. Before allowing the ignition sequence to proceed, it confirms the inducer is running at the correct speed and that combustion gases are being properly vented. When this switch fails — or the hose, port, or inducer itself is faulty — the control board will lock out the furnace before it ever reaches the ignition stage, leaving you with no heat. Typical symptoms include the inducer motor spinning normally but the furnace failing to advance to ignition, or a diagnostic fault code indicating a pressure switch error.

• Part Number: HK06WC091 | SPST (Single-Pole, Single-Throw) | High-Fire configuration | Factory Authorized Part manufactured by Honeywell
• OEM vs Generic: This is a genuine OEM part built to exact factory vacuum setpoint tolerances. Aftermarket pressure switches often use imprecise diaphragm ratings that can cause nuisance lockouts or — more dangerously — fail to detect a true venting fault, creating a safety hazard.
• Install Difficulty: 2/5 — Power down the furnace and disconnect the 24V control wires before starting. Tools needed: a 1/4" nut driver, needle-nose pliers, and a manometer (recommended to verify vacuum at the port after install). Inspect the rubber hose and port for cracks or blockages before replacing the switch alone.
• Warranty: 1-year OEM factory warranty. Ships same business day from our warehouse when ordered before cutoff.

Compatibility: Designed for the Carrier PG8JAA042090AAJA gas furnace. Also fits select Bryant and Payne models sharing the same inducer and pressure switch specification — verify the W.C. (water column) setpoint on your original switch label before ordering. Note: HK06WC091 has been superseded by OEM replacement part HK06MC110; our listing ships the current valid replacement. Questions about fitment? Our HVAC parts specialists verify compatibility before your order ships.