Lennox 14T66 Pressure Switch

The Lennox 14T66 Pressure Switch is a critical dual-stage safety component engineered for 90% efficiency modulating gas furnaces. As a veteran technician knows, maintaining the correct pressure differential is non-negotiable for safe combustion. This OEM Lennox replacement part is factory-calibrated to operate within a specific water column range of 1.00" to 0.25" WC, ensuring the inducer motor pulls the required vacuum before the ignition sequence begins. Designed for high-performance downflow units, it is rated for elevations from 0 to 7500 feet, making it a versatile choice for varied geographic installations.

When dealing with furnace pressure switch stuck open codes, the 14T66 provides the reliable 2-stage sensing needed to monitor combustion air accurately. This combustion air pressure switch kit includes the dual-switch assembly and mounting bracket, facilitating a direct swap for failing 14A41 or 606569-15 components. Integrating this Lennox 14T66 into your service ensures the system meets modulating furnace specifications for flue gas venting and vacuum suction, preventing unsafe gas buildup or short-cycling due to inaccurate draft readings.

• Dual-Stage Precision: Accurate 1.00" - 0.25" WC sensing for modulating furnace sequences.
• Wide Elevation Rating: Reliable performance from sea level up to 7500 feet.
• Direct OEM Compatibility: Replaces Lennox 14A41, 606569-15, and 606569-07 without field modifications.
• Safety Compliance: Essential for monitoring inducer RPM and flue vacuum in high-efficiency systems.

• What causes a pressure switch to stay open? Usually, this indicates a blocked flue, cracked pressure tubing, or a failing inducer motor. Always check for moisture in the lines on 90% efficiency models.
• Is the 14T66 compatible with SLP99 models? Yes, this assembly is the standard replacement for Lennox SLP99DF series furnaces.
• Can I use this switch at high altitudes? This specific part is rated for elevations up to 7500', covering most standard residential applications.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.