Control Board Kit Replacement for MasterTemp MaxETherm NA and LP Pool and Spa Heaters (part numbers 420020007S, 461105) Why you need this control board kit Restores heater electrical control after a failed or malfunctioning control board, bringing ignition, temperature regulation, and safety interlocks back to working . Saves time and avoids full unit replacement by serving as a directfit replacement for the listed heater models. Reduces downtime so pools and spas to normal operation quickly. Key features and benefits Direct compatibility: Designed as a replacement for MasterTemp MaxETherm NA and LP pool and spa heater electrical systems, matching part numbers 420020007S and 461105 for straightforward fit and function. Precise electrical match: Matches original control board connections and signal pathways to integrate with existing wiring and sensors. Compact PCB design: Spaceefficient printed circuit board form factor fits into the original control compartment without modification. Reliable performance: Restores core heater functions including ignition control, temperature setpoint response, and system fault reporting. Installationfriendly: Accepts standard heater connectors and mounting points to simplify replacement. Professional installation or qualified technician recommended for safety and correct operation. Typical applications and use scenarios Emergency : a failed control board to quickly restore heating after a controller fault or component failure. Seasonal maintenance: Keep a spare control board on hand during peak season to minimize disruption from unexpected faults. Equipment refurbishment: Use during heater servicing to aging electronics and ensure consistent control performance. Compatibility and technical notes Replacement for control board part numbers 420020007S and 461105 used in MasterTemp MaxETherm NA and LP pool and spa heaters. Intended for use with the original heater electrical system and wiring harnesses. Verify part numbers and model compatibility before . Follow the heater service manual and local electrical codes during installation. Disconnect power before servicing. This control board kit is a practical option for restoring heater control functions with a directfit replacement for the specified models.