The Carrier HH18HA202 Rollout Switch is a critical safety component designed for gas-fired furnaces and heating systems. Engineered as a manual reset limit switch, this SPST (Single Pole Single Throw) device is calibrated to open the circuit at a fixed 350 degrees F. When excessive heat is detected—typically indicating a flame rollout condition or heat exchanger breach—the switch interrupts the 24V control circuit to shut down the gas valve immediately. This OEM replacement part ensures the system remains offline until a technician inspects the combustion area and manually resets the button. This specific model is the direct Carrier HH18HA202 replacement for SWT1045, maintaining the exact thermal response curves required for ICP, Bryant, and Day & Night HVAC units. For field technicians, verifying the limit switch opening temperature and ensuring a tight mounting fit is essential for preventing nuisance trips and maintaining system integrity.

• Precise Thermal Calibration: Factory-set to 350°F to prevent fire hazards caused by improper venting or secondary heat exchanger failure.
• Manual Reset Mechanism: Forces a professional diagnostic check after a rollout event, ensuring the root cause is addressed before the furnace resumes operation.
• Broad Compatibility: Serves as the primary furnace rollout switch for a wide range of Carrier-produced residential heating equipment.
• High-Temperature Durability: Constructed with ceramic and metal components to withstand the harsh environment of a burner manifold assembly.
• Universal Wiring: Simple SPST configuration allows for quick integration into existing safety loops without modifying wiring harnesses.

What causes a 350-degree rollout switch to trip?
A trip usually indicates a clogged vent pipe, a cracked heat exchanger, or soot buildup on the burners, causing flames to "roll out" toward the manifold rather than entering the heat exchanger cells.

Can the HH18HA202 be used in place of a lower-temperature switch?
No. Always match the OEM temperature rating. Installing a switch with a higher threshold than specified can lead to unsafe operating conditions and equipment damage.

Is the HH18HA202 compatible with other brands?
Yes, this is the designated SWT1045 replacement and fits many Inter City Products (ICP) and older Bryant furnaces where the mounting footprint and temperature rating match.

Item is Non Cancelable / Non Returnable

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.