Product: Replacement Control Board Kit, part number 420020007S What this kit does Direct replacement control board kit for pool and spa heater electrical systems. Restores electronic control of ignition, temperature sensing, and safety interlocks when the original control board fails. Designed to interface with NA and LP model heater electrical systems for straightforward swapin replacement. Key benefits Quick restoration of heater operation to minimize downtime and service calls. Exactfit replacement for compatible heater models to simplify installation and reduce troubleshooting. Maintains original control functions so temperature regulation and safety features operate as intended. Compatibility Compatible with MaxETherm heater models SR333HD, SR400HD, SR200NA. Identified by part number 420020007S to ensure correct match with electrical system wiring and connectors. What to expect A control board kit supplied to a faulty or damaged control board. Works with the existing wiring harness and sensors when matched to the listed heater models and NA and LP model electrical systems. Intended for installers or experienced technicians familiar with pool and spa heater electrical systems. Typical use scenarios a failed control board after an electrical surge that leaves the heater unresponsive to thermostat input. Upgrade a malfunctioning heater control assembly during routine maintenance to restore stable temperature control. a spa heater that cycles erratically by swapping in a matched control board kit to eliminate control electronics as the source of the problem. Notes for buyers Confirm model numbers SR333HD, SR400HD, SR200NA or NA and LP model electrical system compatibility before ordering to ensure correct fit. Recommended for use by qualified service technicians or experienced DIY installers familiar with heater electrical systems and safety procedures.