Lochinvar & A.O. Smith 100076100 Surge Box

The Lochinvar & A.O. Smith 100076100 Surge Box is a critical genuine OEM surge box kit designed to integrate into the high-voltage junction box of specific commercial and residential tankless water heater parts. This component acts as a power surge protector, utilizing high-grade metal oxide varistors (MOVs) to manage transient voltage spikes that can otherwise compromise sensitive integrated controls and blower assemblies. In the field, this unit is frequently required for tankless water heater repair when local grid instability or power outages cause internal protective components to trip or degrade.

For technicians performing HVAC system diagnostics, the 100076100 Surge Box provides a direct-fit replacement for the 320273-128 and EK280 legacy part numbers. It is engineered to meet original manufacturer specifications for Lochinvar, A.O. Smith, and Takagi models, ensuring line-voltage stability and protecting the control module from catastrophic failure. This surge protection device is essential for maintaining the operational integrity of high-efficiency systems in environments prone to electrical noise or frequent storms.

• OEM Compatibility: Guaranteed fit for A.O. Smith, Lochinvar, and Takagi tankless units including TK-540P, T-H3, and T-KD20 series.
• Voltage Spike Mitigation: Safeguards expensive integrated controls and combustion blowers from transient surges.
• Direct Replacement: Simplifies service calls by replacing old part numbers 320273-128 and EK280.
• System Reliability: Protects the internal circuit board, reducing the risk of unplanned downtime in commercial applications.

• When should I replace the surge box? Replace the unit if the system fails to power on after a localized electrical event or if the surge box shows visible signs of thermal stress.
• Is this compatible with Takagi units? Yes, this part is a direct OEM replacement for Takagi tankless models requiring part 100076100.
• Does this protect against direct lightning strikes? While it mitigates grid-based surges, it is not a lightning arrestor; standard electrical safety protocols still apply.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.