Should you buy a Nest Thermostat Trim Kit?

Best answer: Yes, but only if you're buying the new Nest Thermostat (not the Learning or E models) because it's not included with purchase. A trim kit is the best option for covering up cracks and abrasions left behind from removing an old thermostat.

• Cover up the mess: Nest Thermostat Trim Kit ($15 at Amazon)

Nest Thermostat Trim Kit A steel and trim plate

Whichever smart thermostat you buy, your first step must always be to remove your old thermostat. Typically a thermostat's base is either screwed or glued to the wall, or attached to an electrical box. Removing it from the wall will expose holes, paint chips, and other defects, in a rectangular shape that your circular smart thermostat won't fully cover. As for an electrical box, you can't mount a thermostat on one without a steel plate.

If you own or plan on buying a Nest Thermostat, you will likely need either a trim plate or steel plate. Thankfully, the Nest Thermostat Trim Kit includes both, so you don't need to worry about getting the wrong kit.

The trim kit measures 7.09" long and 4.41" tall. While the Nest Thermostat itself is fairly compact, adding in the wide trim kit gives the overall set a much larger presence on your wall. As for the steel plate, it stands at 3.94"x2.68", so it will jut out slightly on the sides but not by much.

Unfortunately, this Trim Kit isn't included by default like it was with the Nest Learning Thermostat and Nest Thermostat E, because it implies that it's an optional purchase. But unless you plan on painting over any wall imperfections before installing your new Nest, it's a necessity. Fortunately, Google sells different four colors, so be sure to pick the plate that matches your thermostat best.

Nest Thermostat Trim Kit Choosing the right color

Like the Nest Thermostat itself, the Trim Kit comes in four different colors. Interestingly, though, they're slightly different than the Thermostat's color options. The Nest Thermostat comes in Snow, Charcoal, Sand, and Fog. The Trim Plate also has Snow and Charcoal but switches things up with Deep Fog and Shell.

The obvious choice is to pick the same color, or closest color, as your thermostat. That would be Deep Fog (which has a deeper greenish shade) with Fog, Shell (a deeper pink) with Sand and the matching Snow and Charcoal sets. However, you could always choose the Snow trim plate regardless so it blends into your white walls and accentuates the thermostat's colors.

Nest Thermostat Trim Kit Installation is easy

Installing a Nest Thermostat requires some rewiring to the wall, which can be a little tricky. But attaching the trim kit itself doesn't add any difficulty to the process. You simply snap the Thermostat base to the trim plate, feed your HVAC wires through the plate and attach them to the thermostat, and then use the included self-tapping mounting screws to attach the pair to your wall.

Once it's wired up, you'll be ready to improve your energy usage and monitor your HVAC health. But before you buy the Trim Kit or the Nest Thermostat, make sure that the thermostat is compatible with your furnace.