Fix a Nest Thermostat C Wire Issue

This Nest Thermostat, I tell ya, while it does have some perks, it has been a handful since I got it. Luckily for me, I managed to get one for free.

Unluckily for me, it's stopped working on numerous occasions and I've frozen my rear end off as of course it waits until the weather is sub-zero.

This time was different though, everything stopped working. As you can see, we have a four wire system.

As it turns out, despite what Nest has said for years that you don't need a C wire (essentially a power wire) to run one of these things, they lied. Or stretched the truth. Either way, turns out, over time without a C wire, eventually it'll stop working. Which is a hassle at bare minimum.

Here's some fancy trickery a technician did to get the heat and a/c working again, but this doesn't allow usage of the fan setting on its own which I like to use. He also rewired the furnace which I was not privy to.

Wholly dissatisfied, I contacted someone else.

What's needed is a Venstar Add-a-Wire that adds a C wire through some creative splitting in its gizmo.

Now, this is definitely a DIY-able task but as Nest was paying for my repair, I went pro. Know your limits though; messing with furnace wiring looks terrifying.

You wire this thing at the furnace and a little splitter at the thermostat. All in all, it's very simple and quite genius.

As you can see, my pro was wow, very pro and wired this thing back up in a very tidy fashion! And as you can see too, there's now a blue wire going into the C slot.

Proof in the pudding, the C wire is detected and all the numbers were reading properly. Haven't had a stitch of an issue since!

Be sure to click the link below to read all the details about this and so many other cool projects around the house!