How can I tell if my Nest is getting power?

Answered by Frank Schwing

When it comes to determining if your Nest thermostat is receiving power, you can check the Device Information > Power section in the Settings menu. Within this section, you will find the Battery subsection, which provides some important readings that indicate the flow of electricity through your thermostat’s wiring.

One of the readings you’ll see is Voc, which stands for Open Circuit Voltage. This reading represents the voltage potential when there is no current flowing through the wires. It is the maximum voltage that your thermostat can receive from your HVAC system. Typically, the Voc reading should be around 24 volts, which is the standard voltage for most HVAC systems in residential homes. If the Voc reading is significantly lower than 24 volts, it could indicate a power issue.

Another reading to look at is Vin, which stands for Input Voltage. This reading represents the actual voltage being received by your Nest thermostat when it is connected to your HVAC system. The Vin reading should ideally be close to the Voc reading, as it reflects the voltage that is actually being utilized by your thermostat. If the Vin reading is significantly lower than the Voc reading, it could indicate a problem with the power supply or the wiring.

Lastly, you’ll find the lin reading, which stands for Input Current. This reading represents the amount of current flowing through your thermostat’s wiring. The lin reading should typically be within a certain range, which can vary depending on your HVAC system. If the lin reading is very low or zero, it could indicate a lack of power flowing to your thermostat.

To ensure that your Nest thermostat is receiving adequate power, you’ll want to check that these readings don’t go below a certain level. While specific thresholds may vary depending on your HVAC system, generally, a Voc reading below 20 volts, a Vin reading significantly lower than the Voc reading, or a very low lin reading could indicate a power issue.

If you notice any of these abnormal readings, it could be indicative of a problem with your thermostat’s power supply or wiring. In such cases, it is advisable to consult a professional HVAC technician to diagnose and resolve the issue. They will have the expertise to troubleshoot and rectify any power-related problems with your Nest thermostat.

Monitoring the Voc, Vin, and lin readings in the Device Information > Power section of your Nest thermostat’s Settings can help you determine if your thermostat is getting proper power. If you notice any significant deviations from the expected readings, it is best to seek professional assistance to address the issue and ensure your thermostat functions optimally.