Honeywell Home DT4R White Room Thermostat Spare | DTS42WRFST20 Wireless

The Honeywell Home DT4R White Room Thermostat Spare DTS42WRFST20 is a spare wireless thermostat head for replacing failed DT4R units or expanding existing Honeywell RF systems. Slim modern design with energy-efficient LED display and full compatibility across evohome, HCC100, and legacy RF products via Ramses II/III protocol.

Key Features

• Spare thermostat only - pairs with existing DT4R, evohome, or HCC100 receivers.
• Ramses II & III RF compatibility works with all Honeywell wireless heating controls.
• Built-in eco-mode timed temperature reduction for energy savings.
• Auto-off LED display with wake-up button conserves battery life.
• Backlit touch buttons ensure easy operation day or night.
• Fuzzy Logic control provides precise temperature regulation.

Why Choose DT4R White Spare Thermostat?

Economical replacement maintains full system performance without buying complete thermostat kits.

Classic white finish matches traditional interiors while delivering modern energy-saving features.

Suitable For

• DT4R replacements (thermostat head failure scenarios).
• Evohome/HCC100 expansions adding wireless thermostats.
• Service stock for Honeywell RF heating installations.

Technical Specifications

• Brand: Honeywell Home by Resideo
• Model: DT4R White Spare Thermostat Head
• MPN: DTS42WRFST20
• GTIN: 5059085002671
• Power Supply: 2 x AA batteries
• Battery Life: Approx. 3.5 years
• Set Point Range: 5 °C to 35 °C
• Display Range: 0 °C to 40 °C
• Sensor: 10k NTC thermistor @ 25 °C
• RF Frequency: ISM 868.0-868.6 MHz (Ramses II/III)
• Range: 30 m residential
• ErP Class: Class V (+3 %)
• Dimensions: 101 x 101 x 54 mm (WxHxD)
• Weight: 0.25 kg
• Warranty: 2 years

Compatibility & Installation

Instant replacement for DT4R white thermostats or spare for evohome underfloor controllers. Simple battery fit and automatic receiver binding. Supports heat pumps, zoning, underfloor heating, zone valves, and 24-230V on/off appliances.