White-Rodgers 3L02-170 Limit Switch

The White-Rodgers 3L02-170 is a high-performance snap disc limit switch engineered for critical safety regulation in furnace and blower applications. Designed as an Open on Rise limit control, this component features a fixed 170°F cut-out temperature, ensuring your HVAC system shuts down safely when thermal thresholds are exceeded. As a manual reset limit switch, it requires a physical reset once tripped, preventing auto-cycling in potentially dangerous over-temperature conditions. This 3/4" flanged airstream mount control is a direct replacement for many OEM units, specifically cross-referencing to the Therm-O-Disc 60T15-330535 series. With a robust SPST switch action and high electrical ratings—10A @ 120VAC and 5A @ 240VAC—this switch provides reliable HVAC high limit safety for both residential and commercial gas/electric package units. The compact design and tab-to-screw terminal adapters ensure an efficient on-job replacement process for technicians.

• Fixed Thermal Protection: Precisely calibrated 170°F cut-out point provides consistent system safety without the drift common in adjustable models.
• Enhanced Safety Logic: The manual reset functionality protects equipment and structures by requiring a site inspection before the system resumes operation.
• Universal Versatility: Standard 3/4" snap disc mounting holes and included terminal adapters allow for rapid installation across multiple brands.
• Industrial Durability: Rated for up to 25A resistive loads, these White-Rodgers limit controls are built to withstand high-cycling environments.

What does 'Open on Rise' mean for this limit switch?
In HVAC safety circuits, 'Open on Rise' signifies that the electrical contacts will break (open) the circuit when the temperature reaches 170°F, immediately cutting power to the gas valve or heating element.

Can I replace an auto-reset switch with this manual reset 3L02-170?
You should only use a manual reset limit control where specified by the manufacturer. If you are replacing an auto-reset limit, a trip may indicate an underlying airflow issue that must be addressed before resetting the switch.

Is this switch compatible with my specific furnace?
The 3L02-170 fits most standard 3/4" flanged mounts. Check your existing part for the "L170" marking or the 60T15-330535 part number to ensure a technical match.

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.