Product overview This replacement control board kit restores temperature regulation and control for compatible pool and spa heaters. It is intended for use when the original control board fails to start the heater or stops displaying status information. Key benefits Restores heater control and temperature regulation when the original board no longer powers up or shows status. Directreplacement fit for compatible heater electrical systems, minimizing installation time and avoiding wiring modifications. Includes the control board and the matching switch membrane pad required for a complete functional replacement. Helps avoid downtime by returning the heater to normal operation without replacing the entire unit. What is included 420020007S(461105) control board 420020029Z(472610Z) switch membrane pad Compatibility Compatible with: Mastertemp 400, Mastertemp 300, Mastertemp 250, Mastertemp 200 StaRite MaxETherm heater models SR200NA, SR333NA, SR400NA, SR200HD, SR333HD, SR400HD, 460805 All NA and LP series pool and spa heater electrical systems Function and performance Primary function is to regulate temperature and manage heater startup and user interface display. Replaces failed or nonfunctional control board assemblies to restore normal control functions and display feedback. Designed to match the electrical connections and control interface of the listed compatible heater models for reliable operation. Practical applications and use cases a control board on a heater that will not start and shows no display or status indicators. Swap in the included membrane pad and control board during routine heater after moisture damage or button failures on the user interface. Use as a maintenance replacement to restore accurate temperature control after intermittent control faults are diagnosed. Notes for installers Verify model compatibility with the heater control compartment before installation. Follow all safety procedures for electrical equipment and disconnect power before replacing the control board. The kit contains the control board and membrane pad needed for the replacement; no additional control components are included.