Add-A-Wire Accessory, Briidea Common Wire Kit for All 24VAC Thermostats (4 to 5 wires), White

My gen 3 has been running well for 5 years without a C-wire. Recently I got a new Trane system and heard many bad things about Trane and Nest without a C-wire. So I decided to get this kit. It was pretty straightforward to install. The hole behind the thermostat was a bit small so I had to dig it a bit bigger (not need to be too big as the diode is very small). Then I changed the existing Y wire to the new C wire (as it is blue) and used the G green wire for the diode. At the control board, just connect according to the included diagram.Then I turned the system back on. The Nest recognized the new C-wire right the way. The battery level has been staying over 3.9v ever since (it used to be 3.75-3.85v).Highly recommended for anyone whose Nest is lacking a c-wire. It will keep your Nest to function a lot longer.

I am an air-conditioning contractor, and have used products like this for the past 15 years. Even veteran contractors often do not know this product exists and it is a lifesaver. Due to the increase in use of Wi-Fi thermostats, which require a common, more people are using similar products. This is because Wi-Fi thermostats require a common . If a common ids required, you must have a minimum of five wires and many homes were wired with four wires if they had single stage heat abd mercury thermostats. This is a common issue with older hones. Another issue is that Low-voltage wiring is very fine and it is hard copper, not stranded. So, age can allow for deterioration and breakage causing problems.Since thermostat wires can be very difficult to pull, depending on if the wire is nailed inside the trusses, inside the walls, in a multi level home or condo, this product can also provide a replacement for a broken wire for a standard stat.This inexpensive product allows us to forgo running a new thermostat wire, at several hundred dollars expense to the customer. We can provide a replacement wire for a daily wine when pulling a new wire is difficult or cost prohibitive, or provide the common needed when needed for a wifi stat when only 4 wires exist. However, it is really designed for a professional to use not for the homeowner. It seems easy enough but truthfully a homeowner risks shorting tge unit or injuring themselves if they don't have the knowledge BBC a s it gets wired inside the air handler/furnace, as well as at the thermostat.

Got this in place of the Emerson version for the Sensi Touch 2. Works exactly how it's supposed to and very easy to install. All functions work and fixes the C wire for this smart thermostat.

Works perfectly and easy to install.I believe the people having issues are trying to get a C wire through the device. But you have to use one existing wire as the C wire and then use the device for (e.g.) Y and G.

Very useful for upgrade to smart thermostat that is missing a C common wire.

The product did the job, and it is a good solution for getting a difficult to access thermostat run with 4+ wires up to the 5+ required to correctly run something like a nest with basic heating and cooling. If you have any less in the wall, it's probably just not worth it for a standard HVAC system. Even with 4 wires and two of these kits, you can only get to 6 wire equivalent, which doesn't run quite everything you would find in a typical house (pick only one of 2 stage heat, 2 stage cooling, and humidifier). If it's even moderately accessible, just buy yourself a nice flex drill and pull in a new 7/8 wire thermostat bundle.Installation was a hassle on my furnace, though. First, the included wires are really short, to the point that I had to extend them just to reach a surface for mounting. Secondly, the extra wires would not fit on the terminal screws along with with the original wires, so I had to crimp spade connectors to each pair. Third, the expectation is to use a wire nut to connect the diode to the blue wire. A bunch of thermostats, mine included, use solid/stiff wire and small holes in the wall. The wire nut did not hold well under that stress, so you may need to either make a larger hole in the wall, or replace the joint with something more sturdy, like a tight mechanical twist and solder.Expect to make minor adjustments to get things working. This type of product isn't suitable for someone without a selection of basic electrical tools (drill, fasteners, shrink wrap, strippers, cutters, crimpers, spare wire, terminal connectors, etc.) and comfort working with them, but I would recommend it otherwise.