The Lochinvar air pressure switch is designed for compatible EnergyRite heater applications where pressure-based airflow monitoring is needed. An air pressure switch is useful because it helps verify proper operating conditions, supporting safer and more dependable heater performance.This replacement is especially useful when the original switch is failing, inaccurate, damaged, or no longer activating correctly. Replacing the switch can help restore dependable system monitoring without replacing the larger heater assembly.The 100166156 is a practical service part when a compatible Lochinvar EnergyRite heater needs an air pressure switch to restore dependable operation. Lochinvar air pressure switch Fits compatible EnergyRite heater applications Helps monitor pressure-related operating conditions Useful when the original switch is inaccurate or failing Supports cleaner and more dependable heater performance