1. Introduzione
This manual provides instructions for the installation, operation, and maintenance of the Venstar T8850 ColorTouch Commercial Thermostat. The T8850 is a digital thermostat designed for commercial applications, offering up to 4 Heat and 2 Cool Stages. It supports gas, electric, or heat pump control systems and features WiFi connectivity for remote management. Users can switch between programmable and non-programmable modes for flexible temperature control.

Figura 1: Fronte view of the Venstar T8850 ColorTouch Thermostat, displaying its sleek design and digital screen.
Funzioni chjave:
- ColorTouch digital display for intuitive control.
- Up to 4 Heat and 2 Cool Stages for comprehensive climate management.
- Compatibility with gas, electric, and heat pump systems.
- Integrated WiFi for remote access and control via a dedicated phone app.
- Switchable programmable and non-programmable modes.
- 7-Day Programmable scheduling and 365-day calendar.
- Weather tracking, Preoccupancy Fan Purge, and up to 4 hours override.
- Controlu di deumidificazione.
2. Setup è Installazione
Proper installation is crucial for the optimal performance of your Venstar T8850 thermostat. It is recommended that installation be performed by a qualified HVAC technician. Ensure power to the HVAC system is turned off at the circuit breaker before beginning installation.
2.1 Unpacking è Inspection
Carefully remove the thermostat from its packaging. Inspect all components for any signs of damage. The package should contain the thermostat unit and the backplate/mounting bracket.

Figure 2: The Venstar T8850 Thermostat alongside its retail packaging, illustrating the product's presentation.
2.2 Muntatura di u termostatu
- Spegnimentu: Disconnect power to the heating and cooling system at the main fuse or circuit breaker panel.
- Elimina u vechju termostat: Carefully remove your old thermostat from the wall. Note the wiring connections before disconnecting them.
- Piastra posteriore di montaggio: Secure the Venstar T8850 backplate to the wall using the provided screws. Ensure it is level.
- cablaggio: Connect the system wires to the appropriate terminals on the backplate. Refer to the wiring diagram provided with your specific installation guide for detailed connections. The T8850 supports various HVAC system types.

Figura 3: Posteriore view of the Venstar T8850 thermostat, revealing the circuit board and clearly labeled wiring terminals for system connection.
2.3 Accensione iniziale è cunfigurazione
- Ripristina l'energia: Once wiring is complete and secure, restore power to the HVAC system.
- Configurazione iniziale: The thermostat will guide you through an initial setup process on its ColorTouch display. This includes setting the time, date, and basic system parameters.
- Cunnessione WiFi: Navigate to the settings menu to connect your thermostat to your local WiFi network. This enables remote control and access to advanced features via the Venstar phone app.
3. Operazione
The Venstar T8850 features an intuitive ColorTouch display for easy operation. The main screen typically shows the current room temperature, desired setpoint, and current operating mode.
3.1 Aghjustà a temperatura
- On the main screen, touch the "Warmer" or "Cooler" buttons to adjust the desired temperature setpoint.
- The display will show the current room temperature and the new setpoint.
3.2 Changing Operating Modes
- Press the "Mode" button on the display to cycle through available operating modes:
- Raffreddamentu: Activates the air conditioning system.
- Riscaldamentu: Attiva u sistema di riscaldamentu.
- Auto: Automatically switches between heating and cooling to maintain the set temperature range.
- Off: Turns off the HVAC system.
3.3 Menu and Advanced Settings
Press the "Menu" button to access advanced settings and features. These include:
- Schedule: Set up 7-day programmable schedules for automated temperature adjustments.
- Smart Fan: Optimize fan operation for comfort and energy efficiency.
- Screensaver: Customize the display screensaver.
- Avvisi: Configure notifications for system events.
- Display: Adjust display brightness and other visual settings.
- Preferenze: Personalize various thermostat behaviors.
- Definite l'ora è a data: Manually adjust time and date if not automatically synchronized.
- Vacation/Away: Set specific temperature profiles for periods of absence.
- Sicurezza: Implement security features to prevent unauthorized changes.
- infurmazione: View infurmazione di sistema è diagnostichi.
- Settings: Access system-level configurations.
3.4 Remote Control via Phone App
Once connected to WiFi, download the Venstar phone application to control your T8850 thermostat remotely. The app allows you to adjust settings, monitor temperatures, and manage schedules from anywhere.
4. Mantenimentu
Regular maintenance ensures the longevity and efficient operation of your Venstar T8850 thermostat.
4.1 Pulizia di u termostatu
- Wipe the screen and exterior casing cù un dolce, damp tela.
- Avoid using abrasive cleaners, solvents, or chemical sprays, as these can damage the display or casing.
4.2 Verifiche di u sistema
- Periodically check the wiring connections at the backplate to ensure they are secure.
- Ensure the thermostat is free from dust and debris, especially around any ventilation openings.
4.3 Calibration Temperature
If you notice a discrepancy between the thermostat's displayed temperature and the actual room temperature (measured by an independent thermometer), you may need to calibrate the internal sensor. This can typically be adjusted within the thermostat's advanced settings menu. Consult the full Venstar T8850 technical documentation for precise calibration steps.
5. Risoluzione di prublemi
This section addresses common issues you might encounter with your Venstar T8850 thermostat.
5.1 Thermostat Not Responding / Blank Display
- Verificate u putere: Ensure the HVAC system's power is on at the circuit breaker.
- cablaggio: Verify all wiring connections are secure at the backplate.
5.2 Prublemi di cunnessione WiFi
- Verificazione di u router: Ensure your WiFi router is powered on and functioning correctly.
- Forza di u Segnu: Check the WiFi signal strength displayed on the thermostat. If weak, consider relocating the router or using a WiFi extender.
- Reboot: Try restarting your WiFi router and then the thermostat (by temporarily cutting power to the HVAC system).
- Reconfigure WiFi: Go to the thermostat's settings menu and reconfigure the WiFi connection.
5.3 Letture di temperatura incorrette
- Ostruzione di u Sensore: Ensure no objects are blocking the thermostat's internal temperature sensor (e.g., furniture, curtains).
- calibrazione: Refer to Section 4.3 on Temperature Calibration to adjust the sensor offset if necessary.
5.4 HVAC System Not Responding to Thermostat
- Selezzione di modu: Verify the thermostat is set to the correct operating mode (Heat, Cool, Auto).
- Set Point: Ensure the desired temperature setpoint is appropriately above (for heating) or below (for cooling) the current room temperature.
- Potenza di u sistema: Confirm the HVAC system itself has power and is operational.
- Assistenza prufessiunale: If the issue persists, contact a qualified HVAC technician.
6. Specificazioni
| Feature | Detail |
|---|---|
| Marca | Venstar |
| Nome di mudellu | Commercial ColorTouch Thermostat |
| Numero di mudellu | T8850 |
| Tipu di cuntrollu | Pulsante |
| Tecnulugia di cunnessione | Wi-Fi, Wireless (Wi-Fi) |
| Fonte d'energia | Elettricu |
| Voltage | 3 Volts |
| Pesu di l'articulu | 8 once |
| Dimensioni di u produttu | 2 x 6.2 x 4.7 inch |
| Tipu di visualizazione | Digitale |
| Retroilluminazione | Iè |
| Tipu di muntatura | Muntu à u muru |
| Funzioni spiciali | Phone App Available, Temperature Sensor, Dehumidification Control, 7-Day Programmable, 365 Day Calendar, Weather Tracking, Preoccupancy Fan Purge, Up to 4 Hours Override |
7. Garanzia è Support
7.1 Garanzia di u fabricatore
The Venstar T8850 Commercial Thermostat comes with a Garanzia di u fabricatore di 1 anniQuesta garanzia copre i difetti di materiali è di fabbricazione in cundizioni d'usu nurmale. Per piacè cunservate a vostra prova d'acquistu per e richieste di garanzia.
7.2 Assistenza tecnica
For technical assistance, troubleshooting beyond this manual, or warranty inquiries, please contact Venstar customer support. Refer to the official Venstar websitu o imballaggio di u pruduttu per l'infurmazioni di cuntattu più recenti.
When contacting support, please have your thermostat model number (T8850) and a description of the issue ready.





