Owner's Manual
Table Of Contents
- Installation Guide
- User Guide
- Table of Contents
- Thermostat Features
- Getting the most from the T9 Smart Thermostat
- Using Your Thermostat
- Using the Honeywell Home App
- Basic thermostat operation
- Wi-Fi settings and connectivity
- Scheduling options
- Advanced Features
- Frequently Asked Questions (FAQs)
- Troubleshooting
- Specifications
- Regulatory Information
- Warranty
- C-Wire Adapter Guide
- Wire Labels
- FCC Compliance Statement
33 33-00478–03
Troubleshooting
If you have difficulty with your thermostat, please try the following suggestions. Most problems can be corrected quickly and
easily.
Display is blank
• Check circuit breaker and reset if necessary.
• Make sure power switch for heating and cooling is on.
• Make sure furnace door is closed securely.
• Make sure the C-wire is connected.
• Make sure R/Rc slider tab is set correctly (see wiring diagrams).
Heating or cooling system does not respond
• Press Menu > System Mode > Heat > Done to set the system to Heat mode. Make sure the desired temperature is higher
than the indoor temperature.
• Press Menu > System Mode > Cool > Done to set the system to Cool mode. Make sure the desired temperature is lower than
the indoor temperature.
• Check circuit breaker and reset if necessary.
• Make sure power switch for heating and cooling system is on.
• Make sure furnace door is closed securely.
• Wait 5 minutes for the system to respond.
Temperature settings do not change
Make sure desired temperature is within acceptable ranges:
• Heat: 40 °F to 90 °F (4.5 °C to 32.0 °C)
• Cool: 50 °F to 99 °F (10.0 °C to 37.0 °C)
Aux heat runs in cooling
• For heat pump systems, verify there is not a wire attached to W on the UWP.
Cool runs with a call for heat
• For heat pump systems, verify there is not a wire attached to W on the UWP.
Sensor will not connect
• Press and hold Connect on the wireless sensor for 15 seconds. The LED will turn Amber. Return to the thermotat menu and
press Menu > Devices and Sensors. Follow the on-screen instructions to add the sensor.