We take cryptocurrency — so the coins you hold can buy real hardware.Pay in crypto, spend it on real hardware. Free insured shipping worldwide over $399. Plain, unbranded boxes, sent from Germany.Free insured shipping over $399. Your rate is locked for 30 minutes once checkout opens.Rate locked 30 minutes. Every item sealed, serial-checked and covered by a 24-month warranty.Sealed, 24-month warranty.

Saved items Sign in
Venstar wireless thermostat accessory module, compact white plastic enclosure with terminal connectors

Venstar

Venstar Add-A-Wire Thermostat Accessory 474-0410

SKU CH-W1G1-0MHH1

Adds a thermostat wire without running new cable, enabling five-wire stats on four-wire systems or repairing broken connections

  • Product typeThermostat Accessories
  • Adds a thermostat wire without pulling new cable
  • Fixes a damaged conductor in existing HVAC wiring
  • Lets a 5-wire thermostat run on 4 conductors
  • Expands 5 conductors to function as 6 wires
  • Replaces Totaline P474-0410 and Carrier 33CSACC-AW parts

What the Add-A-Wire Does

The Venstar Add-A-Wire accessory adds a conductor to an existing thermostat cable so a five-wire thermostat can operate on four wires or a six-wire thermostat can operate on five. It is intended for HVAC installers and homeowners who cannot pull new cable through finished walls.

When to Use It Instead of New Cable

The device replaces running an extra wire when the existing bundle is short one conductor, when a wire is damaged, or when a common wire is missing from a four-wire heat-only system. It also lets one thermostat control two zones. The jump is worth it whenever fishing new cable would require opening walls or ceilings.

Installation and Common Pitfalls

The module connects at the equipment end and the thermostat end with standard low-voltage terminals; no special tools are required. The most frequent issue is connecting the green and yellow diode leads to the R or C terminals, which the instructions prohibit. Incorrect polarity on the diode will prevent the added signal from passing.

How it compares

Measured against everything we stock in Thermostats & Thermostat Accessories, at today’s prices. Recalculated every night.

Price $42.99
Cheaper than about 67% of the 286 comparable items (median $78.49).

Specifications

Product
Product typeThermostat Accessories

Questions about this item

What wiring does the Venstar Add-A-Wire 474-0410 need at the thermostat to add a common wire?

It works with a 4-wire system, using the existing green and yellow wires to create a common connection without running new cable.

Which step is often missed when installing the Venstar Add-A-Wire 474-0410 accessory?

The green and yellow wires of the Diode Y must not be connected to the R or C terminal of the thermostat, or the accessory will not function correctly.

When would the Venstar Add-A-Wire 474-0410 need to be replaced?

Replace it if the thermostat loses the added common wire function, indicating the accessory has failed or the wiring has been altered.

More in Thermostats & Thermostat Accessories

Similar items