Lennox 12J17 Relay

The Lennox 12J17 Relay is a heavy-duty 24V DPDT N/O Sequencer Relay engineered for precision timing in electric heat applications and furnace blower control. This genuine OEM component, also identified as Lennox 104284-02, utilizes a thermal sequencer design with a voltage-compensated PTC (Positive Temperature Coefficient) heater. The double-pole, double-throw (DPDT) configuration with normally open contacts ensures reliable staging of heating elements, preventing simultaneous high-amperage draws that can trip breakers. As a veteran-grade replacement part, it is commonly found in Lennox ECB25 series and ECB29 heat kits. The 12J17 provides consistent varied sequence timing to manage load distribution across the bimetal disc assembly. This relay is essential for maintaining the intended delay-on and delay-off cycles required for system safety and airflow management. Its robust construction is designed to withstand the high-cycle demands of residential and light commercial HVAC air handlers.

• OEM Compatibility: Exact drop-in replacement for Lennox part 104284-02 and 111002748.
• Enhanced Safety: Normally open (N/O) contacts ensure circuits fail-safe in the open position.
• Durable Thermal Switch: PTC heater technology provides stable, repeatable timing across a wide range of ambient temperatures.
• High Load Capacity: DPDT configuration allows for the management of multiple heating elements or combined blower/heater sequencing.
• Industry Standard: Fits a broad range of ECB electric heat sections and air handlers.

• Can this relay replace a SPST sequencer? While the 12J17 is a DPDT relay, it can typically replace lower-pole count relays if the wiring is correctly adapted; however, always verify the 24V coil requirements and contact ratings first.
• What does "Varied Sequence" mean for this part? It refers to the specific timing delays calibrated into the bimetal disc, ensuring that heating elements turn on and off in a staggered fashion.
• Is this relay used for blower control? Yes, in many Lennox electric furnaces, the sequencer manages the timing of the blower motor in conjunction with the heating elements to prevent "cold blow" at startup.

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.