Wiring & Connectors

Connectors & Wiring

The HVAC Wiring & Connectors category focuses on the conductors, terminations and splices that tie an HVAC system together. Clean wiring is about more than appearance—it’s critical for safety, system reliability and future service. This section is built for technicians who want the right mix of thermostat wire, control cable, line-voltage leads, terminals, lugs, wire nuts, butt splices and specialty connectors that stand up to heat, vibration and moisture around air handlers, condensers and rooftops.

Here you’ll find low-voltage thermostat wire for controls, multi-conductor cable for zoning and accessories, high-temperature appliance wire, crimp terminals, ring and spade lugs, butt splices, lever connectors, wirenuts and harness repair kits. Many options are UL listed and color-coded to speed troubleshooting and reduce wiring errors. Stocking the right wiring and connectors helps you restore power, clean up previous “hack” installs and prepare systems for future upgrades like smart stats, IAQ accessories and zoning controls.

• Thermostat & control wiring – 18-gauge multi-conductor cable for conventional and heat pump systems.
• Line-voltage appliance wire – high-temperature, properly rated conductors for motors and heaters.
• Crimp terminals & lugs – ring, spade, flag and disconnect terminals in common HVAC sizes.
• Splices & wirenuts – twist-on, butt splices and lever connectors for secure joins.
• Harness repair & specialty connectors – kits for OEM board, motor and sensor connections.

When choosing HVAC wiring and connectors, always confirm voltage, temperature rating, insulation type, conductor gauge, strand count and environment. Low-voltage control wiring must be sized for run length and load, while line-voltage conductors must match overcurrent protection and equipment MCA/MOP. Terminals and splices must be rated for copper vs aluminum, solid vs stranded conductors, and indoor vs outdoor use. Use the Compare tools on this page to review ratings, size ranges, insulation type and connection style.

Pro tip: Before modifying wiring, document existing color codes, terminal markings, equipment diagrams and any non-standard splices. Take photos of control boards, contactors, transformers and thermostat sub-bases so you can restore or improve terminations with the correct wire gauge, connectors and strain relief—and leave the next technician a clean, readable layout.