Bard HVAC 8403-089 Thermostat

The Bard 8403-089 Thermostat is a field-proven 1H/1C programmable thermostat built on the Honeywell T4 Pro Series platform. This unit serves as the direct replacement for Bard 8403-057 and Honeywell TH3110D1040, providing a seamless upgrade path for legacy single-stage residential and light commercial HVAC systems. Designed for technical efficiency, it features a UWP mounting system and a tool-less terminal block, significantly reducing installation time in the field. The auto changeover functionality and integrated logic for 7-day, 5-2, or 5-1-1 scheduling ensure tight setpoint control across a temperature range of 37°F to 102°F. Operating on either 24VAC common wire or battery power, this non-Wi-Fi thermostat is a reliable solution for technicians requiring a durable interface without the complexity of wireless commissioning. The large backlit digital display and intuitive push-button interface provide the reliability expected by service contractors managing Bard wall-mount units or standard split systems.

Key Benefits for Technicians

• Direct Compatibility: Engineered as the official Bard replacement thermostat for obsolete 8403-057 and TH3110D1040 models.
• Streamlined Installation: Utilizes the Honeywell UWP mounting system and push-to-connect terminals for faster wiring.
• Advanced Logic: Includes auto heat/cool changeover and smart response technology for precise climate management.
• Versatile Powering: Dual-power options allow for C-wire permanent power or AA battery backup for flexible field application.
• Maintenance Alerts: Integrated filter change reminders help ensure long-term system performance and air handler efficiency.

Common Questions

Is the Bard 8403-089 compatible with multi-stage heat pumps?
No, this model is designed specifically for 1 Heat / 1 Cool stage systems. For multi-stage applications, a T6 Pro or Bard-specific multi-stage controller should be used.

What is the difference between the 8403-089 and a standard T4 Pro?
The 8403-089 is the Bard HVAC certified version of the T4 Pro, ensuring it meets the specific performance and compatibility profiles required for Bard wall-mount and package equipment.

Does this unit require a C-wire for operation?
While a 24VAC common wire is recommended for constant display illumination and reliability, the unit can operate solely on battery power if necessary.

Disclaimer: While we strive for 100% accuracy, product data and specifications are subject to change. Please contact our team to confirm compatibility or technical details before purchasing.