OEM Lennox Integrated Control Board — 12L42
OEM Guaranteed
Same-Day Ship
30-Day Returns
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The genuine OEM Lennox 12L42 control board is the central circuit board that manages ignition, safety monitoring, and motor timing in your Lennox furnace. It reads the thermostat call for heat, energizes the igniter and gas valve, confirms flame, and sequences the inducer and blower to keep your system heating safely and efficiently.
Common failure symptoms: Typical signs of a bad board include no ignition, repeated safety lockouts, short-cycling, a blower that won't shut off, or no reaction to thermostat commands. Burnt relays, corroded traces, and blown onboard fuses are common culprits, often flagged by the board's diagnostic LED.
Why OEM matters: Lennox control logic is tuned to the exact sensors, motors, and safety devices in your furnace. The OEM 12L42 board provides an exact-fit replacement with correct terminals and firmware, avoiding the compatibility and safety issues common to aftermarket substitutes — and keeping your Lennox warranty intact.
Shipping Information
- Orders placed before 3PM CST ship same business day
- Standard delivery: 2-5 business days
- Express shipping available at checkout
- Free shipping on orders over $75
- Tracking number emailed upon shipment
Return Policy
- 30-day returns on unused parts in original packaging
- Electrical parts (capacitors, contactors, control boards) are final sale once installed
- Email info@nationalhvacparts.com to initiate a return
- Refunds processed within 5-7 business days