Heil Quaker ICP 1170929 Pressure Switch

The Heil Quaker ICP 1170929 Pressure Switch is a critical safety component designed for induced draft furnaces. Primarily utilized in Heil, Tempstar, and Comfortmaker gas-fired equipment, this OEM replacement part monitors the negative pressure generated by the inducer motor. Operating at a factory-set .35" WC (Water Column), this SPST (Single Pole Single Throw) switch ensures the venting system is clear and the flue gases are being safely exhausted before the ignition sequence proceeds. If the switch detects insufficient vacuum or a blocked vent, it breaks the 24V circuit to prevent hazardous operation.

This unit features a standard 1/4" barb connection for the vacuum hose and two male spade terminals for electrical integration. As a technician, identifying a failed furnace pressure switch often involves ruling out obstructed inducer ports or cracked silicone tubing. This specific model replaces previous iterations, including part numbers 1011739 and 02427576-00, maintaining high-precision sensitivity for low-pressure applications typically found in 80% and 90% AFUE residential furnaces.

• Ensures safe furnace operation by verifying the proper venting of combustion gases before ignition.
• Compatible with a wide range of ICP brands including Heil, Tempstar, Arcoaire, and KeepRite.
• Hardened diaphragm construction designed to resist the corrosive effects of furnace condensate.
• Exact 0.35" WC set point eliminates nuisance tripping on systems requiring specific low-pressure thresholds.
• Standardized 1/4" barb fitting allows for a direct, leak-free connection to existing pressure hoses.

What are the symptoms of a bad furnace pressure switch?
Common indicators include the furnace failing to ignite, an inducer motor that runs continuously without a flame, or the control board displaying a 3-flash fault code. Technicians should verify the pressure with a manometer and check for continuity across the terminals once the inducer reaches speed.

Can I use a switch with a different WC rating?
No. Pressure switches are calibrated specifically for the venting requirements and blower capacity of the unit. Installing a switch with a higher or lower rating than .35" WC can lead to unsafe operation or frequent system lockouts.

What causes these switches to fail intermittently?
Intermittent failures are often caused by moisture buildup in the vacuum line, a restricted heat exchanger, or a dirty inducer blower wheel that is unable to pull a consistent draft.

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.