Honeywell Thermostat Troubleshooting
Honeywell Home thermostats (T5, T6, T9, T10) connect via WiFi and work with Alexa and Google Home. The T6 Pro also has a Z-Wave version.
Won't Connect to WiFi
WiFi Setup
- Download the Honeywell Home app
- Create an account or sign in
- Tap + to add device and select thermostat
- Follow prompts to connect thermostat to 2.4GHz WiFi
Connection Issues
- Most models only support 2.4GHz WiFi
- Check that router isn't blocking new devices
- Move thermostat to a better WiFi location if possible (usually not)
- Reset WiFi: Menu > WiFi Setup > Disconnect
Thermostat Not Heating/Cooling
Check Settings
- Verify system is set to Heat, Cool, or Auto (not Off)
- Check the setpoint temperature is above/below current temp
- Review schedule - it may be in a different period
- Check if "Hold" is set, overriding the schedule
Equipment Issues
- Check breaker/fuse for HVAC system
- Verify wiring matches installation guide
- Ensure C wire is connected (or battery-powered models have good batteries)
- Check if furnace/AC has a safety switch tripped
T9/T10 Room Sensor Issues
Sensor Not Pairing
- Insert battery in sensor
- In the app, go to thermostat > Add Room Sensor
- Sensor should pair automatically
- If not, try removing and reinserting the battery
Sensor Offline
- Replace battery (CR2032)
- Check distance from thermostat (30-200 ft depending on walls)
- Re-pair if it won't reconnect
Z-Wave T6 Pro Issues
For the Z-Wave version:
- Pair to your Z-Wave hub instead of WiFi
- Put hub in inclusion mode, then select "Z-Wave" on thermostat
- Supports S2 security for encrypted control
- Works with SmartThings, Hubitat, Home Assistant
Schedule Problems
- Geofencing overrides schedule based on phone location
- Check geofencing settings aren't causing issues
- Adjust schedule in app or on thermostat
- Use "Temporary Hold" vs "Permanent Hold" appropriately