Lochinvar & A.O. Smith 100208510 Sequencer

The Lochinvar & A.O. Smith 100208510 Sequencer is a critical 24V control component designed for staged heating element activation in high-demand residential and commercial systems. Engineered as a direct replacement for RLY2707 and RLY2707K, this 24V sequencer ensures that heating elements engage in a specific timing sequence, preventing high-amperage inrush that can trip breakers or damage sensitive HVAC electrical components. As a veteran-grade staged heating control, it utilizes a reliable bimetal disc mechanism to manage the resistive load of electric furnace heat strips, providing the necessary delay between stages for stable system performance.

For contractors performing electric furnace troubleshooting, this unit is the standard choice for restoring proper cycling to Lochinvar and A.O. Smith heating systems. Its compact footprint allows for a seamless fit into existing control cabinets, and the staged heat strip control logic is factory-calibrated to maintain consistent discharge air temperatures. Whether you are replacing a stuck-open relay or dealing with a system that short-cycles due to uneven element activation, the 100208510 delivers the heavy-duty reliability required for professional service calls.

• Direct OEM Compatibility: Specifically engineered to replace RLY2707 and RLY2707K, ensuring precise electrical and physical fitment.
• Circuit Protection: Prevents massive power draws by staggering the activation of heating elements, protecting 24V control circuits and main breakers.
• Enhanced System Stability: Eliminates rapid temperature fluctuations and "cold blow" issues common with failing HVAC sequencers.
• Durable Construction: Built to withstand the high-cycle demands of peak winter operation in A.O. Smith and Lochinvar units.

• What are the signs of a failing 100208510 sequencer? Look for heating elements failing to turn on, elements staying on when the thermostat is satisfied (stuck closed), or the furnace tripping the main circuit breaker immediately upon a call for heat.
• Calculated delay: How long should I wait for the sequencer to close? These units typically take 30 to 90 seconds for the bimetal to heat up and close the high-voltage contacts. If terminals don't show continuity after 2 minutes of 24V power, the unit is likely defective.
• Is this an exact replacement for the RLY2707? Yes, the 100208510 is functionally identical and the current manufacturer-specified replacement for both RLY2707 and RLY2707K.

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.