Carrier HH18HA490 Rollout Switch

The Carrier HH18HA490 Rollout Switch is a critical safety component designed for high-efficiency gas furnaces. This manual reset rollout switch is engineered to monitor temperatures within the burner compartment, providing essential protection against flame rollout conditions. Functioning as a Single-Pole Single-Throw (SPST) device, it is calibrated to open the electrical circuit at approximately 290 degrees F, effectively shutting down the system if hazardous heat levels are detected. As a genuine Carrier HH18HA490 replacement, this part ensures that your equipment maintains its original safety specifications and operational integrity.

For technicians performing maintenance or repairs, it is important to note that the HH18HA490 is the direct updated version for the HH18HA292 and HH18HA291 models. This furnace rollout limit switch features a compact disc-style design that fits seamlessly into the burner box assembly of various Carrier, Bryant, and Payne units. When a trip occurs, the manual reset button requires physical intervention, alerting the contractor to underlying issues such as cracked heat exchangers, blocked venting, or improper gas pressure that must be addressed before resuming furnace operation.

• OEM Compatibility: Specifically designed to replace older HH18HA292 and HH18HA291 models without modification.
• Precise Thermal Response: Opens at a strictly calibrated 290°F to prevent cabinet damage and ensure fire safety.
• Manual Override Security: Requires a manual reset to ensure the cause of the over-temperature condition is diagnosed by a professional.
• Reliable SPST Action: Provides a dependable "normally closed" circuit that breaks immediately upon reaching the temperature threshold.
• High-Efficiency Integration: Optimized for modern gas-fired furnaces where precise combustion monitoring is required.

• Why does my rollout switch keep tripping? Frequent tripping typically indicates a serious combustion issue, such as a soot-clogged heat exchanger, restricted exhaust flues, or failing inducer fans.
• Can I bypass the HH18HA490 for testing? No. Bypassing a safety limit is non-compliant with safety standards and can lead to catastrophic equipment failure or fire.
• Is the HH18HA490 compatible with my older HH18HA292? Yes, the HH18HA490 is the official updated replacement part designed to meet or exceed the specifications of the HH18HA292.

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.