Model 420020007S Control Board Kit for Pool and Spa Heater Electrical Systems What this part does Replaces the electrical control board that manages ignition, gas valve operation, and control signals in NA and LP model pool and spa heaters. Restores reliable electronic control when the original board fails or produces error codes. Key benefits Direct compatibility with MasterTemp 200 250 300 400 400HD models, providing a straightforward replacement option for affected heaters. Designed to match the original board footprint and connector layout to minimize installation time and reduce the need for wiring changes. Built as a complete control board kit to heater functions to normal operation without replacing the whole unit. Why you need it Replacing a failed control board avoids costly full heater replacement and reduces downtime. Keeps your heater operating safely and consistently by restoring proper control of ignition and system sequencing. Useful for pool professionals and homeowners who need a reliable replacement part on hand. Important attributes Function: Electrical control board kit for ignition and system control functions in pool and spa heaters. Compatibility: Fits NA and LP models and compatible with MasterTemp 200 250 300 400 400HD heater models. Size and fit: Compact replacement designed to match original board dimensions and mounting points for easier installation. Construction: Standard printed circuit board design with protective enclosure and factory style connectors to interface with existing wiring. Performance: Restores control responsiveness and system sequencing to original equipment behavior. Typical use scenarios Homeowner replacing a failed control board that prevents the pool heater from starting after diagnosing an electrical fault. Service technician carrying a replacement kit to complete same day repairs on a residential or light commercial pool heater. Maintenance team installing a replacement board to resolve intermittent ignition or control errors during seasonal startup. Note Confirm model compatibility before installation by matching model numbers and connector types. Installation may require basic electrical skills and proper power isolation.