Google Nest Thermostat Troubleshooting Steps

How to tell if manual heating is on
Troubleshooting Heat Link's connection
On your thermostat, you’ll see an error beginning with the
letter H when Heat Link is disconnected.
In order to control your system with your Nest thermostat or
the app, you’ll need to troubleshoot the connection.

Google Nest Thermostat Specifications

General

Sensors	Temperature, Humidity, Proximity, Ambient Light
Type	Smart Thermostat
Remote Control	Yes, via Google Home app
Operating Temperature	32° to 104°F (0° to 40°C)
Compatibility	Works with most 24V heating and cooling systems, including gas, electric, forced air, heat pump, radiant
Connectivity	Wi-Fi 802.11b/g/n @ 2.4GHz, Bluetooth Low Energy
Color Options	Snow, Charcoal, Sand, Fog
Power Source	24V common wire (C-wire)
Features	Remote control via app, energy-saving features, scheduling, HVAC monitoring
Voice Control	Compatible with Google Assistant and Amazon Alexa
Warranty	1-year limited warranty
Dimensions	3.3 inches in diameter x 1.07 inches deep