Honeywell Home DT4M White OpenTherm Wired Room Thermostat | Modulating Digital Heating Control

The Honeywell Home DT4M White OpenTherm Wired Room Thermostat is an advanced modulating thermostat for precise room temperature control with OpenTherm® compatible boilers, heat pumps, and zoning systems. Featuring slim modern design, energy-efficient LED display, and intelligent modulation control for maximum boiler efficiency.

Key Features

• OpenTherm® modulation reduces boiler cycling and improves energy efficiency.
• Energy-saving LED display auto-off technology with wake-up button activation.
• Backlit touch buttons and clear status icons for intuitive user interface.
• Built-in eco offset provides timed temperature reduction for energy savings.
• Fuzzy Logic control optimises modulation for accurate temperature maintenance.
• Frost protection maintains minimum 5 °C setpoint when system is off.

Why Choose Honeywell Home DT4M White?

Delivers superior energy efficiency through continuous boiler modulation while maintaining simple user operation and modern aesthetics suitable for contemporary interiors.

ErP Class V (+3%) rating with backward compatibility for OpenTherm® systems and 2-year warranty.

Suitable For

• OpenTherm® modulating boilers and combi boilers requiring precise load control.
• Heat pumps and underfloor heating systems benefiting from modulation.
• Zone valve applications and multi-zone heating installations.

Technical Specifications

• Brand: Honeywell Home by Resideo
• Model: DT4M White OpenTherm Wired Thermostat
• MPN: DT41SPMWT30
• Control Protocol: OpenTherm® (modulating)
• Power Supply: 2 x AA batteries (OpenTherm® Smart Power option)
• Battery Life: Approx. 3.5 years
• Set Point Range: 5 °C to 35 °C
• Display Range: 0 °C to 40 °C
• Sensor Type: 10k NTC thermistor @ 25 °C
• ErP Class: Class V (+3 %)
• Dimensions: 101 x 101 x 23 mm (HxWxD)
• Weight: 105 g
• Terminal Capacity: Max 2.5 mm²
• Operating Temperature: 0 °C to 40 °C
• Warranty: 2 years

Installation & Operation

Simple wired wall-mount installation with flip-up wiring platform. User menu configures heating/cooling modes, eco offset duration, and frost protection. Installer menu provides advanced OpenTherm® parameters, cycle rate adjustment, setpoint limits, and commissioning functions.