3L01-170 Copeland Comfort Control (White Rodgers) L170-40F
3L01-170 Copeland Comfort Control (White Rodgers) L170-40F
The 3L01-170 Snap Disc Limit Switch (White-Rodgers / Copeland Comfort Control) is an automatic reset temperature safety control designed to protect HVAC and heating equipment from excessive operating temperatures. Featuring a 170°F fixed cut-out temperature and 130°F fixed cut-in temperature, this open-on-rise limit switch interrupts the electrical circuit when temperatures exceed safe limits and automatically resets once temperatures return to normal operating conditions.
Cross-Reference
- 3L01-170
- 3L01170
- L170-40F
- 60T11-610012
- White-Rodgers 3L01-170
- Copeland Comfort Control 3L01-170
Direct OEM
White-Rodgers 3L01-170
Compatible Brands
- White-Rodgers
- Emerson
- Copeland
- York
- Coleman
- Luxaire
- Goodman
- Universal HVAC Applications
Application
Used in heating and HVAC equipment to:
- Prevent overheating of equipment components
- Open the control circuit at 170°F
- Automatically reset at 130°F
- Protect heat exchangers, motors, and control circuits
- Maintain safe operating temperatures
- Provide automatic temperature-based safety protection
Related Components
- Snap Disc Limit Switch
- High Limit Control
- Fan Switch
- Fan & Limit Control
- Blower Relay
- Furnace Control Board
- Transformer
- Temperature Sensor
- Contactor
Technician Notes
The 3L01-170 is an automatic reset, open-on-rise snap disc limit switch. Under normal conditions, the contacts remain closed. When the sensing surface reaches 170°F, the contacts open to interrupt the circuit and protect equipment from overheating. The switch automatically resets when temperature drops to approximately 130°F.
Repeated limit trips are usually caused by restricted airflow, dirty coils, plugged filters, improper blower operation, blocked vents, or excessive heat buildup. Always correct the root cause before replacing the switch.
Common Symptoms of Failure
- Equipment shuts down on high temperature
- Open limit fault code
- Intermittent furnace operation
- Heating system lockout
- No continuity through switch contacts
- Repeated nuisance shutdowns
- Reduced heating performance
- Failure to restart after an overheat condition
Installation Tips
- Disconnect power before servicing.
- Match temperature ratings exactly to the original switch.
- Verify switch action is "Open on Rise."
- Mount securely on the original sensing surface.
- Inspect wiring terminals for heat damage or corrosion.
- Check airflow and blower performance before replacement.
- Confirm continuity and proper operation after installation.
- Test the unit through a complete heating cycle.
Recommended Inspection Items
- Blower motor operation
- Air filter condition
- Heat exchanger temperature
- Supply and return airflow
- Evaporator coil cleanliness
- Wiring terminals
- Furnace control board
- Venting system condition
- Temperature rise across equipment
Controls, Temperature, 130 degrees F Fixed Cut-in Temperature, 170 degrees F Fixed Cut-out Temperature, Open on Rise Switch Action, Snap Disc Auto Reset Limit Switch (60T11-610012)
