Replacement electronic control board for gas pool and spa heaters designed to restore reliable operation and extend service life. Key benefits Restores heater function: replaces a failed control board to get your pool or spa heating working again. Faster, more responsive control: optimized optocoupler module delivers about 30 percent faster signal response for more stable ignition and control behavior. Robust protection: builtin safeguards against overheat, overvoltage, and shortcircuit help reduce the chance of repeated failures. Durable construction: FR2 copper foil laminate and SR waterproof coating resist moisture and corrosion for longer service life. Support and peace of mind: 12hour response guarantee for installation and usage questions plus a 1year and exchange policy. Features Direct replacement compatibility: fits MasterTemp 200, 250, 300, and 400 heater models and compatible with MaxETherm SR200NA and SR333NA models. Works with most NA and LP pool and spa heaters. Not compatible with 200HD units. Upgraded components: solidstate capacitors and precisionsoldered parts improve electrical stability and longevity. Faster response electronics: optimized optocoupler module reduces response time by approximately 30 percent compared with standard boards. Triplelayer protection: integrated overheat, overvoltage, and shortcircuit protection to help prevent damage from common fault conditions. Moistureresistant finish: SR waterproof coating helps protect circuitry in humid or wet environments. Labtested durability: constructed and tested for roughly twice the lifespan of typical replacement boards under comparable conditions. Practical applications Emergency : swap this board into a MasterTemp 250 heater to restore ignition and control after an electronic board failure. Routine replacement upgrade: an aging control board in a seasonal pool heater to reduce the likelihood of midseason breakdowns. Maintenance for commercial or residential spas: install as part of preventive maintenance to improve reliability in use spa installations. Compatibility and notes Direct replacement for MasterTemp 200, 250, 300, and 400 models. Compatible with MaxETherm SR200NA and SR333NA models. Suitable for most NA and LP pool and spa heaters; not for 200HD units. If you need help with installation or troubleshooting, support is available with a 12hour response guarantee. A 1year and exchange policy applies. This replacement board focuses on improved response, enhanced protection, and moistureresistant construction to provide a reliable or upgrade for compatible pool and spa gas heaters.