Standby mode with frost protection
Easy installation
Simple user interface
Override functionality
Suitable for Sundial S and Y Plan systems or for additional zones in an S Plan Plus system


Honeywell T4R (Y4H910RF4003) is a wireless battery operated thermostat with optional OpenTherm control via the wireless receiver box, offering easy switch-over from an existing wireless receiver box. Designed for domestic and light commercial properties, the T4 Series of programmable thermostats simplifies temperature scheduling, offering a level of usability and automated control your customers now expect from today’s technology. With standardised fittings and wiring, the T4 Series also simplifies the installation process.

Honeywell T4R Programmable Modulating OpenTherm Thermostat (Y4H910RF4003) has a clear user-friendly digital display with easily identifiable icons and simple push-button access to configuration menus. An easy override functionality allows customers to quickly make occasional changes without any hassle. 

The T4R has automatic summer and winter time changes for all-year efficient control and a standby mode with frost protection for added peace of mind. It is also Suitable for Sundial S and Y Plan systems or for additional zones in an S Plan Plus system.

The T4 Series uses standard thermostat fittings and connections, offering installers an easy, inexpensive choice when it comes to replacing an old thermostat. After fitting, T4 Series thermostats are ready to use!


Form FactorThermostat
Pack QuantityTotal 1 Piece(s)