Google Nest Power Connector C-Wire Adapter - Snow 3.98in, 24VAC Stable Power for Nest Thermostats

The Google Nest Power Connector is a compact C-wire substitute that supplies steady 24 VAC power to compatible Nest thermostats without adding new wires.

Many Nest thermostats run without a dedicated common (C) wire, but some heating and cooling systems — like heating-only, cooling-only, zone-controlled, or certain heat-pump setups — need continuous 24 VAC to maintain reliable operation. The Nest Power Connector is designed to bridge that gap affordably and with minimal installation: it mounts at the furnace air handler or zone controller and connects to existing terminals so you don’t have to run a new cable through walls. Designed specifically for Nest devices, this small accessory helps prevent brownouts, unexpected reboots, and repeated low-battery alerts when a system lacks a C wire.

How does the Nest Power Connector provide power when there’s no C wire?

The connector converts the furnace or air handler’s 24 VAC circuit into a stable source for the thermostat by wiring into the control board at the equipment end. It does not require running a new C conductor to the thermostat; instead, it completes the circuit at the source so the Nest sees continuous power.

• Plugs into furnace/air handler or zone controller terminals
• Works with 24 VAC systems only, delivering a continuous common reference
• Specifically engineered for Nest thermostats to avoid compatibility issues
• Compact 3.98-inch layout fits into control compartments

Which heating and cooling systems need this adapter?

The Power Connector is intended for 24 VAC systems that either lack a C wire or have wiring that intermittently fails to supply steady power. It’s not suitable for millivolt or high-voltage systems, and it should not be used where a factory-installed C wire already meets requirements.

• Ideal for heating-only or cooling-only control boards
• Useful for zone-controlled systems where each zone lacks a dedicated C
• Compatible with standard 24 VAC HVAC control circuits only
• Not compatible with millivolt or line-voltage furnaces and boilers

How difficult is installation and what tools do I need?

Installation is designed for a straightforward DIY job for anyone comfortable working near the furnace control board. The connector mounts inside the air handler or zone controller, connects to specific terminals, and includes step-by-step instructions. If you’re unsure, a professional HVAC technician can install it quickly.

• Mounts at the furnace air handler or zone controller—no wall fishing required
• Includes illustrated instructions and labeled wires for easy connection
• Requires basic hand tools: screwdriver and possibly wire stripper
• Professional installation recommended if you’re unfamiliar with HVAC control boards

What should I be aware of before buying?

Confirm your system runs on 24 VAC and that you don’t already have a functioning C wire at the thermostat. The Power Connector won’t work on non-24 VAC setups and is designed specifically for Nest devices; check compatibility with your thermostat model and furnace control board before purchase.

• Only for 24 VAC systems — verify voltage at the control board
• Not for millivolt or high-voltage HVAC systems
• Made with 46% post-consumer recycled materials and rated for −30° to 60°C
• Google will send alerts via device, app, and email if issues arise

Who is this for? The Google Nest Power Connector is aimed at homeowners and HVAC technicians who want a simple, cost-effective solution to power a Nest thermostat when a dedicated C wire is missing or unreliable. It’s especially helpful for older homes, single-function heating or cooling systems, and zone-controlled setups where running new thermostat wiring is impractical. If you have a 24 VAC system and want fewer thermostat power interruptions without re-cabling walls, this accessory provides a compact, Nest-specific fix that installs at the equipment end.