Nest Thermostat Troubleshooting

Below, you can find the troubleshooting guide for different models of Nest thermostats (the 3rd generation and 4th generation). The manuals are written in the form of tables for your convenience: they enlist common technical issues and the ways to fix the problems. The instructions were provided by the manufacturers and are quite easy to follow. You shouldn’t face any challenges during the troubleshooting process – guidelines are quite simple. However, if you cannot perform the task on your own, don’t hesitate to contact the repair service provider.

Nest Learning D3 Thermostat Troubleshooting

ProblemSolution
If the Nest thermostat isn't getting enough power from W or Y and there is no Common wireWhile we find that in the vast majority of homes the Nest Thermostat can charge its built in battery by power sharing from the regular heating and cooling wires. But in some rare cases a common wire is needed to deliver consistent power to the Nest Thermostat while allowing normal operation of the heating and cooling system. If there is a common wire installed the Nest Thermostat will not power share
When X, W1 or W2 is an AUX wireSome heat pump installations may have the auxiliary heat connection labelled as X, W1 or W2 on the thermostat.
You should verify that the X wire on the old thermostat is not a common wire. Once you're sure, you can assume that the X is the auxiliary heat and should be inserted into the AUX/W2 connector on the Nest Thermostat
Compressor and Auxiliary Heat Lockout Temperatures for Heat Pumps Requires Wi-FiBoth auxiliary and compressor lockout temperatures can be changed
The lockout temperatures are only enforced when the Nest Thermostat is connected to Wi-Fi so it can track outdoor temperatures. If Wi-Fi is not enabled, Auxiliary heat will come on automatically when it takes longer than expected to reach the current target temperature

Nest T200577 Thermostat Troubleshooting

SymptomWhat’s going onSteps to fix
Nest doesn’t turn on after installation. Red LED blinking on front.The internal battery is low and needs to charge.If you leave it where it is, it will slowly charge and eventually turn on. This can take an hour or two.
If you have a mini-USB cable and wall charger you can charge it more quickly over USB.
You need to restart or reset the settings on the thermostat.You may need to reset the settings if: • You need to restart the thermostat.Follow these steps to access the RESET settings:
• Reset Nest Sense features1. Press the ring to bring up the menu.
• To help with troubleshooting Wi-Fi issues.2. Turn the ring and select SETTINGS.
• The thermostat needs to be reconfigured.3. Turn the ring and select RESET.
4. Select one of the following options: CANCEL, RESTART, SCHEDULE, AUTO- AWAY, NETWORK, TO DEFAULTS.
Nest doesn’t turn on after installation. No LED blinking on the front of the unit.The power was never turned back on.Nest doesn’t turn on until it senses both the that wires are hooked up and power is coming to those wires.
This may happen if you’ve forgotten to turn the power back on to the HVAC system or if you turned the power back on, but there was a fuze or breaker blown during the installation process.
Use normal electrical troubleshooting techniques to isolate the issue to either the fuse/breaker box or a fuse on the HVAC controller board.
Your customer is seeing a question mark on their Nest when they use one of the Nest apps.The Nest apps will show a question mark over the thermostat when the Nest servers can’t communicate with the device. This may happen if:First, you should verify that the customer’s Internet connection is working and that their Wi- Fi network is online.
• The customer’s Internet Service Provider is down.If it is, check the Nest system status in the upper right of nest.com/support. Nest will publish maintenance or outage information there.
• The customer’s router is incompatible with Nest.The last thing to check is if the customer’s Wi-Fi router is compatible with Nest.
• The Nest servers are down or undergoing maintenance.
Forgot Lock CodeCustomer has forgotten the lock code to their NestNest can be remotely unlocked by logging onto the Nest Account paired with their device from the Nest Web app or from the Nest Mobile app.