Westinghouse 626435R Furnace Limit Switch 220/200F 3 Inch

Product Description

The WESTINGHOUSE 626435R is an auto-reset furnace limit switch rated to open at 220 degrees F and close at 200 degrees F. This thermal safety device monitors supply-air or heat exchanger temperatures inside a forced-air furnace and interrupts the burner circuit when temperatures exceed the set point, protecting the heat exchanger from overheat damage. Once temperatures drop back to the closing threshold, the switch resets automatically without manual intervention. The 3-inch insert mount fits into the furnace plenum or blower compartment panel. HVAC technicians install this switch as a direct OEM-style replacement during routine safety inspections or after a nuisance-trip diagnostic.

This limit switch is suited for residential and light-commercial forced-air gas or oil furnace applications. The 3-inch insert style fits through a standard knockout or drilled opening in the furnace casing, positioning the sensing element inside the airstream or near the heat exchanger. It is commonly replaced when a furnace short-cycles, when the existing limit switch fails closed or open, or as part of a heat exchanger inspection and safety-device service. The 1/2-degree differential between the open and close set points provides stable operation without excessive cycling.

Key Features

• Auto-reset operation — returns to closed position automatically once temperature drops to 200 degrees F
• Opens at 220 degrees F to protect the heat exchanger from overtemperature conditions
• 3-inch insert length fits standard furnace casing cutouts
• 1/2-degree operating differential for stable switching without nuisance cycling
• Single-speed rated — suitable for single-blower furnace configurations

Compatibility

Designed as an OEM-style replacement limit switch for residential and light-commercial forced-air furnaces requiring a 220 degrees F opening, 200 degrees F closing, auto-reset, 3-inch insert limit switch.

Installation Notes

A licensed HVAC technician should install this limit switch. Shut off all power to the furnace at the disconnect and set the thermostat to off before removing the existing switch. The insert should be fully seated through the furnace panel so the sensing element is positioned correctly in the airstream — improper insertion depth will cause false trips or no-trip conditions. After installation, restore power and verify proper furnace operation through a complete heating cycle before returning the system to service.

Technical Specifications

• Opening Temperature: 220 degrees F
• Closing Temperature: 200 degrees F
• Reset Type: Auto Reset
• Insert Length: 3 inches
• Operating Differential: 1/2 degree F
• Speed Rating: 1-Speed
• Application: Furnace

Standard Information

• Brand: WESTINGHOUSE
• Manufacturer Part Number: 626435R