The Lennox 59W22 is an OEM replacement L140-40F high-limit switch engineered to protect Lennox furnaces from dangerous overheating conditions. When supply air temperatures exceed the rated setpoint, this limit switch interrupts the burner circuit, preventing heat exchanger damage and ensuring safe system operation.
Product Overview
The L140-40F designation identifies the key operating parameters of this limit switch. It is designed to open the circuit at 140°F and features a 40°F differential, meaning the switch automatically resets and closes the circuit once temperatures fall back to 100°F. This automatic reset functionality helps restore normal furnace operation without requiring manual intervention after a high-temperature event.
Key Features
- OEM Lennox replacement part — ensures proper fit and function
- L140-40F rating: opens at 140°F, resets at 100°F (40°F differential)
- Automatic reset operation for convenient system recovery
- Protects heat exchanger and furnace components from thermal damage
- Interrupts burner circuit on high-temperature detection
- Direct replacement for Lennox furnace applications requiring the 59W22 limit switch
Application
- Designed as a direct OEM replacement for compatible Lennox furnace models
- Ideal for HVAC technicians performing furnace maintenance, repair, or component replacement
- Suitable for residential and light commercial Lennox furnace installations
Specifications
- Brand: Lennox
- Part Number / SKU: 59W22
- Limit Switch Model: L140-40F
- Open (Trip) Temperature: 140°F
- Differential: 40°F
- Reset Temperature: 100°F
- Reset Type: Automatic
