OEM Lennox GP3 Controller — 13J79
OEM Guaranteed
Same-Day Ship
30-Day Returns
Secure Checkout
The Lennox 13J79 (part 104490-01) GP3 controller is a genuine OEM control board that governs the operating logic of your Lennox equipment, sequencing components, monitoring safety inputs, and coordinating staging so the system responds correctly to thermostat demand. As the central circuit board, it processes sensor feedback and drives the relays and outputs that keep the unit running safely and efficiently.
Common failure symptoms: the system not starting on a call, erratic or short cycling, blower or stages failing to energize, fault or diagnostic LED codes, no response to the thermostat, or a control that has no output despite proper incoming power. Board failures frequently follow power surges, moisture intrusion, or aging solder joints and relays.
Why OEM matters: the GP3 controller is programmed with Lennox-specific firmware, timing, and safety logic matched to your exact model. The factory 13J79 ensures correct relay ratings, terminal layout, and control sequences — aftermarket or reflashed boards can misfire equipment or bypass built-in protections. Replacing with the genuine OEM controller restores dependable, factory-rated operation of your Lennox system.
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