The Hydro-Quip ECO2 and ECO3 18 inch high-limit temperature sensor is designed for compatible systems built after May 2003 in supported non-VH configurations. A high-limit sensor is useful because it helps the control system recognize unsafe temperature conditions and contributes to the protective logic that keeps the system operating more safely.This replacement is especially useful when the original sensor is inaccurate, has stopped working, or no longer fits the supported post-5/03 non-VH system requirements. Matching the correct application range is key to keeping the replacement dependable.The 34-0201D is a practical service part when a compatible Hydro-Quip ECO2 or ECO3 system needs renewed high-limit sensing for more reliable protection. Hydro-Quip ECO2 and ECO3 18 inch high-limit temperature sensor Designed for compatible post-5/03 non-VH systems Helps support dependable over-temperature protection Useful when the original sensor is inaccurate or failed Supports cleaner and more accurate service work