Every electrical or HVAC contractor should know how to install a thermostat, but the rising popularity of smart thermostats deserves special attention. As Internet of Things (IoT) technologies become more common, knowing how to manage these newer alternatives will become critical to building contractors’ success.
By the end of 2021, 19.6 million smart thermostats were installed in the U.S. That number could nearly double within five years. More businesses will want to integrate these systems into their buildings as this trend continues, so contractors must know how to install them. Here’s how to do that.
1. Find a Compatible System
The first step to installing a smart thermostat is to check its compatibility with the rest of the building. Not every device can work with every type of HVAC system. High-voltage systems, ductless AC, renewable HVAC and other unique considerations have specific compatibility requirements that may limit applicable options.
Many smart thermostat manufacturers provide compatibility lists to help narrow down possible solutions. Contractors that are unsure should contact these companies to ask about their specific situation.
It’s also important to consider compatibility with existing IoT infrastructure. Smart gadgets operate on several distinct platforms that don’t always work together. Consequently, contractors should check what IoT platform the building uses and ensure their thermostat supports that system.
2. Shut Off HVAC Power
Just as when installing a conventional thermostat, contractors should disable power to the HVAC system. Some buildings have separate breakers for heating and cooling systems, so it may take some searching to find the right switch. Remember to shut off power to the entire system, not just the room the thermostat is in.
In some cases, the thermostat may remain on even after shutting off the power. If that happens, the device has a battery backup. Consult the manufacturer’s instructions to disable or remove this backup. Only begin working when the thermostat shows no signs of power.
3. Take Note of the Wiring
Once the power is off, remove the faceplate from the old thermostat. It should come off by pulling on it, but some models have a latch or screw that holds it in place.
With the faceplate off, take a picture of the thermostat’s wiring. Modern cables have standardized color codes, but pre-2001 wires may not comply with these standards. Some thermostat cables may also have the same characteristics but serve different purposes, so modern color codes may not offer much information. Taking a picture for reference will help connect everything appropriately later, despite this obstacle.
It’s important to label cables that don’t have unique colors. Attach a sticker with a letter designating the wire’s terminal to each line to streamline the wiring process when installing a new thermostat.
4. Disconnect the Old Thermostat
After labeling and photographing all the wires, it’s time to remove the old thermostat completely. This process is the same as when contractors install a thermostat without smart features.
Lift the clamps or loosen the screws at each terminal to disconnect the wires, and pay attention to the cable’s condition to see if any are frayed or exposed, requiring replacement. Unscrew the backplate and gently take it off the wall while holding the wires. Tape the cables to the wall or a pencil to prevent them from slipping into the cavity.
Take this time to clean the wall behind and around the backplate. If the smart thermostat is a different size than the old model, contractors may also want to paint this patch to ensure it matches the rest of the wall.
5. Add a C-Wire if Necessary
In some cases, installing a smart thermostat requires adding a C-wire to ensure it has constant power. Not every IoT thermostat needs a C-wire, but some manufacturers require one on every model, so check with the OEM to determine the device’s wiring needs.
Some smart thermostats come with a C-wire installation kit contractors can use if the building lacks this wiring. If the HVAC control board has no C-wire terminal and the thermostat doesn’t come with one of these kits, contractors can use a 24-volt adapter to plug these wires into a nearby outlet.
6. Mount and Wire the New Backplate
Mounting a new backplate for a smart device is the same as installing a thermostat without smart features. Use a level to line it up evenly and drill holes into the wall if the backplate doesn’t match the old ones. Take the wires off the wall and gently pull them through the backplate before screwing the plate on.
With the wires pulled through, screw the backplate into place. Using a hand screwdriver is best as an electric drill may create too much torque, damaging the plate. Once it’s secure, refer to the labels and picture of the old wiring to connect the cables to the correct terminals.
7. Attach the Faceplate and Restore Power
Once all the wires are connected, it’s time to attach the faceplate. This should snap into place, but some models may have latches or screws.
Go back to the breaker and turn the HVAC system’s power back on. There could be a wiring issue if the faceplate on the smart thermostat doesn’t light up. Turn the power off again, disconnect the faceplate and inspect the cables, ensuring they’re in the right place.
8. Connect the Thermostat to Wi-Fi
A conventional setup would be finished at this point, but there’s one more step to install a smart thermostat. These devices need a Wi-Fi connection to connect to other devices, including end users’ smartphones. Talk to the building owner or business occupying the space to learn the Wi-Fi network and password and follow the manufacturer’s instructions for connecting the thermostat.
Contractors wishing to thoroughly impress their clients should suggest connecting these devices to a guest network instead of the business’s primary Wi-Fi. There are roughly 5,200 attacks on IoT devices each month, and these gadgets can act as gateways to more sensitive systems on the same network if breached. Keeping them separate will minimize risks.
Learning to Install a Smart Thermostat Opens New Opportunities
Contractors that know how to install a smart thermostat can appeal more to increasingly tech-minded clients. More commercial properties are looking to implement IoT devices, so understanding gadgets like smart thermostats will become an increasingly important skill. Learning these steps can help contractors stay competitive in this shifting market.
