✨ New Arrivals Just Dropped!Explore
HomeStore
Honeywell Home DT4R White Wireless Room Thermostat & Receiver | YT42WRFT20 RF Digital Heating Control
Honeywell Home DT4R White Wireless Room Thermostat & Receiver | YT42WRFT20 RF Digital Heating Control
Honeywell Home
Wireless RF
evohome Thermostat Compatible
On/Off Control
Heat Pump Ready
Relay Receiver Included
SKU / MPN
YT42WRFT20
Model Name
DT4R
Colour
White
Control Type
On/Off (non-modulating)
Connectivity
RF 868 MHz wireless
The Honeywell Home DT4R is a battery-powered wireless room thermostat with on/off control, designed for residential heating and cooling applications in homes and apartments. It is supplied as a complete pack including a basic wireless relay receiver that wires directly to the boiler or appliance — no thermostat cable back to the heat source is needed. The DT4R features a slim, modern design with a large LED segment display, backlit captive-touch buttons, and an auto display-off function to conserve battery life. It uses the Ramses II and Ramses III radio frequency protocol, making it backwards and forwards compatible with the wider Honeywell Home RF ecosystem. The thermostat unit itself can be connected to an evohome multi-zone system; however the relay receiver included in this pack is not compatible with evohome — a separate BDR91A relay receiver is required to integrate the relay function into evohome and other home automation and heating control systems. The DT4R is Resideo's designated successor to the DT92 / DT92E range.
Key Features
- Complete wireless pack — thermostat and relay receiver included, ready to install
- No thermostat wiring required — receiver wires to appliance only; thermostat is fully wireless
- Large LED segment display — clear temperature and status readout at a glance
- Backlit captive touch buttons — responsive, intuitive interface
- Auto display-off — screen switches off when not in use to extend battery life
- Eco mode — temporarily reduces setpoint to lower energy consumption
- Boost mode — temporarily raises setpoint for short periods of extra warmth
- Fuzzy logic control — anticipates heat loss for stable, accurate room temperature
- Ramses II & III RF protocol — backwards compatible with existing Honeywell Home RF products including BDR91A
- Thermostat compatible with evohome multi-zone system and HCC100 underfloor heating controller — included relay receiver is not evohome-compatible (BDR91A required, sold separately)
- Drop-in replacement for DT92, DT92E, DT92E1000
- ErP Class IV (+2%) — meets European energy labelling requirements
- Up to 1.5 years battery life from 2 × AA batteries (included)
What's in the Box
- Honeywell Home DT4R white wireless room thermostat
- Wireless relay receiver (wires to boiler / appliance; 230V AC mains powered; not evohome-compatible)
- 2 × AA batteries
- Wall mounting hardware
- Installation guide (includes QR code linking to installation videos)
⚠️ Included relay receiver is not evohome-compatible: The relay receiver supplied in this pack controls the boiler or appliance for standalone use only. It cannot be connected to or managed by the Honeywell Home evohome system or other home automation and heating control systems. To use the relay with evohome, the Honeywell Home BDR91A wireless relay box is required and is available to purchase separately.
System Compatibility
| Application / System | Compatible? | Notes |
|---|---|---|
| Gas or oil combi boiler (230V) | ✓ | Primary use case; on/off switching via included relay receiver |
| Conventional (heat-only) boiler | ✓ | On/off demand switching via included relay receiver |
| Heat pump (air-to-water, ground source) | ✓ | 24–230V on/off signal; heat pump must accept simple on/off demand input |
| 2-port zone valves | ✓ | On/off demand control; standard zone valve wiring via receiver |
| Underfloor heating zone control | ✓ | Via HCC100 multi-zone underfloor heating controller (sold separately) |
| Honeywell Home evohome | ✓ | Thermostat only — the DT4R thermostat integrates as a zone thermostat within evohome. The included relay receiver is not evohome-compatible; a BDR91A (sold separately) is required to connect the relay to evohome |
| Solid fuel boiler | ✓ | On/off demand; boiler must accept an external thermostat input |
| Direct 240V electric heating | ✗ | Not compatible — Resideo explicitly states "not with electric heating / 240V"; use wired DT4 (non-R) |
| OpenTherm® modulating control | ✗ | On/Off model only — for modulating control specify DT4R modulating variants (YT43 series) |
Technical Specifications
| Manufacturer | Resideo (Honeywell Home) |
| Model | DT4R |
| SKU / MPN | YT42WRFT20 |
| Colour | White |
| Control Mode | On/Off |
| Radio Frequency | 868.0–868.6 MHz ISM band |
| RF Range (max) | 30 m in typical residential building |
| RF Protocol | Ramses II / Ramses III |
| Thermostat Power | 2 × AA batteries (included) |
| Battery Life | Up to 1.5 years |
| Receiver Power Supply | 230V AC mains |
| Appliance Voltage (Switched) | 24–230V AC |
| Max Setpoint | 35°C |
| Operating Temperature | 0°C to 40°C |
| Temperature Sensor | 10kΩ @ 25°C NTC thermistor |
| Control Algorithm | Fuzzy logic |
| Display Type | LED segment (auto-off) |
| ErP Classification | Class IV (+2%) |
| Approvals | EMC 2014/30/EU · LVD 2014/35/EU · R&TTE 1995/5/EC |
| Display Indicators | Heat, Cool, Wireless signal, Eco, Off, Low battery, Warning |
✓ Drop-in replacement for DT92 / DT92E / DT92E1000: The DT4R uses the Ramses II RF protocol and is fully backwards compatible with existing Honeywell Home RF receivers. In most cases the existing receiver can be retained and the DT4R thermostat simply bound to it — the spare receiver from the pack is not required.
ℹ️ On/Off only — not suitable for direct electric heating or OpenTherm® modulating: This model switches a 24–230V on/off demand signal and cannot modulate heat output. For OpenTherm® modulating control, specify the DT4R modulating range (YT43MRFWT30 white · YT43MRFBT32 black · YT43MRFGT31 grey). For 240V direct electric heating, a wired DT4 variant is required.
Frequently Asked Questions
Does this come with a receiver?
Yes. The YT42WRFT20 is supplied as a complete pack including a wireless relay receiver that wires to the boiler or appliance. No separate receiver purchase is needed for a new standalone installation.
Can I use the BDR91A with this thermostat?
Yes. If you need the relay to connect to evohome or other home automation and heating control systems, the Honeywell Home BDR91A is compatible with the DT4R thermostat and is available to purchase separately. The relay receiver included in this pack is for standalone boiler switching only and is not evohome-compatible.
Will this work with my evohome system?
Partially. The DT4R thermostat unit can be integrated as a zone thermostat within an existing Honeywell Home evohome multi-zone system. However, the relay receiver included in this pack is not compatible with evohome — it can only be used for standalone boiler switching. To connect the relay to evohome or other home automation and heating control systems, the Honeywell Home BDR91A wireless relay box is required and is available to purchase separately.
Is it a direct replacement for the DT92E?
Yes. Resideo markets the DT4R as the direct successor to the DT92, DT92E, and DT92E1000. Ramses II compatibility means the thermostat will pair with receivers originally installed for those models in most cases.
Can I use it with a heat pump?
Yes, for heat pumps that accept a simple on/off 24–230V switching signal. It is not suitable for heat pumps requiring modulating or OpenTherm® communication — for those, specify the DT4R modulating variants (YT43 series).
Are other colours available?
Yes. The DT4R on/off wireless range is available in White (YT42WRFT20), Grey (YT42GRFT21), and Black (YT42BRFT22). Modulating wireless variants are available in the same three colours (YT43 series).
$37.32
Original: $106.62
-65%Honeywell Home DT4R White Wireless Room Thermostat & Receiver | YT42WRFT20 RF Digital Heating Control—
$106.62
$37.32More Images
Honeywell Home DT4R White Wireless Room Thermostat & Receiver | YT42WRFT20 RF Digital Heating Control
Honeywell Home
Wireless RF
evohome Thermostat Compatible
On/Off Control
Heat Pump Ready
Relay Receiver Included
SKU / MPN
YT42WRFT20
Model Name
DT4R
Colour
White
Control Type
On/Off (non-modulating)
Connectivity
RF 868 MHz wireless
The Honeywell Home DT4R is a battery-powered wireless room thermostat with on/off control, designed for residential heating and cooling applications in homes and apartments. It is supplied as a complete pack including a basic wireless relay receiver that wires directly to the boiler or appliance — no thermostat cable back to the heat source is needed. The DT4R features a slim, modern design with a large LED segment display, backlit captive-touch buttons, and an auto display-off function to conserve battery life. It uses the Ramses II and Ramses III radio frequency protocol, making it backwards and forwards compatible with the wider Honeywell Home RF ecosystem. The thermostat unit itself can be connected to an evohome multi-zone system; however the relay receiver included in this pack is not compatible with evohome — a separate BDR91A relay receiver is required to integrate the relay function into evohome and other home automation and heating control systems. The DT4R is Resideo's designated successor to the DT92 / DT92E range.
Key Features
- Complete wireless pack — thermostat and relay receiver included, ready to install
- No thermostat wiring required — receiver wires to appliance only; thermostat is fully wireless
- Large LED segment display — clear temperature and status readout at a glance
- Backlit captive touch buttons — responsive, intuitive interface
- Auto display-off — screen switches off when not in use to extend battery life
- Eco mode — temporarily reduces setpoint to lower energy consumption
- Boost mode — temporarily raises setpoint for short periods of extra warmth
- Fuzzy logic control — anticipates heat loss for stable, accurate room temperature
- Ramses II & III RF protocol — backwards compatible with existing Honeywell Home RF products including BDR91A
- Thermostat compatible with evohome multi-zone system and HCC100 underfloor heating controller — included relay receiver is not evohome-compatible (BDR91A required, sold separately)
- Drop-in replacement for DT92, DT92E, DT92E1000
- ErP Class IV (+2%) — meets European energy labelling requirements
- Up to 1.5 years battery life from 2 × AA batteries (included)
What's in the Box
- Honeywell Home DT4R white wireless room thermostat
- Wireless relay receiver (wires to boiler / appliance; 230V AC mains powered; not evohome-compatible)
- 2 × AA batteries
- Wall mounting hardware
- Installation guide (includes QR code linking to installation videos)
⚠️ Included relay receiver is not evohome-compatible: The relay receiver supplied in this pack controls the boiler or appliance for standalone use only. It cannot be connected to or managed by the Honeywell Home evohome system or other home automation and heating control systems. To use the relay with evohome, the Honeywell Home BDR91A wireless relay box is required and is available to purchase separately.
System Compatibility
| Application / System | Compatible? | Notes |
|---|---|---|
| Gas or oil combi boiler (230V) | ✓ | Primary use case; on/off switching via included relay receiver |
| Conventional (heat-only) boiler | ✓ | On/off demand switching via included relay receiver |
| Heat pump (air-to-water, ground source) | ✓ | 24–230V on/off signal; heat pump must accept simple on/off demand input |
| 2-port zone valves | ✓ | On/off demand control; standard zone valve wiring via receiver |
| Underfloor heating zone control | ✓ | Via HCC100 multi-zone underfloor heating controller (sold separately) |
| Honeywell Home evohome | ✓ | Thermostat only — the DT4R thermostat integrates as a zone thermostat within evohome. The included relay receiver is not evohome-compatible; a BDR91A (sold separately) is required to connect the relay to evohome |
| Solid fuel boiler | ✓ | On/off demand; boiler must accept an external thermostat input |
| Direct 240V electric heating | ✗ | Not compatible — Resideo explicitly states "not with electric heating / 240V"; use wired DT4 (non-R) |
| OpenTherm® modulating control | ✗ | On/Off model only — for modulating control specify DT4R modulating variants (YT43 series) |
Technical Specifications
| Manufacturer | Resideo (Honeywell Home) |
| Model | DT4R |
| SKU / MPN | YT42WRFT20 |
| Colour | White |
| Control Mode | On/Off |
| Radio Frequency | 868.0–868.6 MHz ISM band |
| RF Range (max) | 30 m in typical residential building |
| RF Protocol | Ramses II / Ramses III |
| Thermostat Power | 2 × AA batteries (included) |
| Battery Life | Up to 1.5 years |
| Receiver Power Supply | 230V AC mains |
| Appliance Voltage (Switched) | 24–230V AC |
| Max Setpoint | 35°C |
| Operating Temperature | 0°C to 40°C |
| Temperature Sensor | 10kΩ @ 25°C NTC thermistor |
| Control Algorithm | Fuzzy logic |
| Display Type | LED segment (auto-off) |
| ErP Classification | Class IV (+2%) |
| Approvals | EMC 2014/30/EU · LVD 2014/35/EU · R&TTE 1995/5/EC |
| Display Indicators | Heat, Cool, Wireless signal, Eco, Off, Low battery, Warning |
✓ Drop-in replacement for DT92 / DT92E / DT92E1000: The DT4R uses the Ramses II RF protocol and is fully backwards compatible with existing Honeywell Home RF receivers. In most cases the existing receiver can be retained and the DT4R thermostat simply bound to it — the spare receiver from the pack is not required.
ℹ️ On/Off only — not suitable for direct electric heating or OpenTherm® modulating: This model switches a 24–230V on/off demand signal and cannot modulate heat output. For OpenTherm® modulating control, specify the DT4R modulating range (YT43MRFWT30 white · YT43MRFBT32 black · YT43MRFGT31 grey). For 240V direct electric heating, a wired DT4 variant is required.
Frequently Asked Questions
Does this come with a receiver?
Yes. The YT42WRFT20 is supplied as a complete pack including a wireless relay receiver that wires to the boiler or appliance. No separate receiver purchase is needed for a new standalone installation.
Can I use the BDR91A with this thermostat?
Yes. If you need the relay to connect to evohome or other home automation and heating control systems, the Honeywell Home BDR91A is compatible with the DT4R thermostat and is available to purchase separately. The relay receiver included in this pack is for standalone boiler switching only and is not evohome-compatible.
Will this work with my evohome system?
Partially. The DT4R thermostat unit can be integrated as a zone thermostat within an existing Honeywell Home evohome multi-zone system. However, the relay receiver included in this pack is not compatible with evohome — it can only be used for standalone boiler switching. To connect the relay to evohome or other home automation and heating control systems, the Honeywell Home BDR91A wireless relay box is required and is available to purchase separately.
Is it a direct replacement for the DT92E?
Yes. Resideo markets the DT4R as the direct successor to the DT92, DT92E, and DT92E1000. Ramses II compatibility means the thermostat will pair with receivers originally installed for those models in most cases.
Can I use it with a heat pump?
Yes, for heat pumps that accept a simple on/off 24–230V switching signal. It is not suitable for heat pumps requiring modulating or OpenTherm® communication — for those, specify the DT4R modulating variants (YT43 series).
Are other colours available?
Yes. The DT4R on/off wireless range is available in White (YT42WRFT20), Grey (YT42GRFT21), and Black (YT42BRFT22). Modulating wireless variants are available in the same three colours (YT43 series).
Product Information
Product Information
Shipping & Returns
Shipping & Returns
Description
Honeywell Home
Wireless RF
evohome Thermostat Compatible
On/Off Control
Heat Pump Ready
Relay Receiver Included
SKU / MPN
YT42WRFT20
Model Name
DT4R
Colour
White
Control Type
On/Off (non-modulating)
Connectivity
RF 868 MHz wireless
The Honeywell Home DT4R is a battery-powered wireless room thermostat with on/off control, designed for residential heating and cooling applications in homes and apartments. It is supplied as a complete pack including a basic wireless relay receiver that wires directly to the boiler or appliance — no thermostat cable back to the heat source is needed. The DT4R features a slim, modern design with a large LED segment display, backlit captive-touch buttons, and an auto display-off function to conserve battery life. It uses the Ramses II and Ramses III radio frequency protocol, making it backwards and forwards compatible with the wider Honeywell Home RF ecosystem. The thermostat unit itself can be connected to an evohome multi-zone system; however the relay receiver included in this pack is not compatible with evohome — a separate BDR91A relay receiver is required to integrate the relay function into evohome and other home automation and heating control systems. The DT4R is Resideo's designated successor to the DT92 / DT92E range.
Key Features
- Complete wireless pack — thermostat and relay receiver included, ready to install
- No thermostat wiring required — receiver wires to appliance only; thermostat is fully wireless
- Large LED segment display — clear temperature and status readout at a glance
- Backlit captive touch buttons — responsive, intuitive interface
- Auto display-off — screen switches off when not in use to extend battery life
- Eco mode — temporarily reduces setpoint to lower energy consumption
- Boost mode — temporarily raises setpoint for short periods of extra warmth
- Fuzzy logic control — anticipates heat loss for stable, accurate room temperature
- Ramses II & III RF protocol — backwards compatible with existing Honeywell Home RF products including BDR91A
- Thermostat compatible with evohome multi-zone system and HCC100 underfloor heating controller — included relay receiver is not evohome-compatible (BDR91A required, sold separately)
- Drop-in replacement for DT92, DT92E, DT92E1000
- ErP Class IV (+2%) — meets European energy labelling requirements
- Up to 1.5 years battery life from 2 × AA batteries (included)
What's in the Box
- Honeywell Home DT4R white wireless room thermostat
- Wireless relay receiver (wires to boiler / appliance; 230V AC mains powered; not evohome-compatible)
- 2 × AA batteries
- Wall mounting hardware
- Installation guide (includes QR code linking to installation videos)
⚠️ Included relay receiver is not evohome-compatible: The relay receiver supplied in this pack controls the boiler or appliance for standalone use only. It cannot be connected to or managed by the Honeywell Home evohome system or other home automation and heating control systems. To use the relay with evohome, the Honeywell Home BDR91A wireless relay box is required and is available to purchase separately.
System Compatibility
| Application / System | Compatible? | Notes |
|---|---|---|
| Gas or oil combi boiler (230V) | ✓ | Primary use case; on/off switching via included relay receiver |
| Conventional (heat-only) boiler | ✓ | On/off demand switching via included relay receiver |
| Heat pump (air-to-water, ground source) | ✓ | 24–230V on/off signal; heat pump must accept simple on/off demand input |
| 2-port zone valves | ✓ | On/off demand control; standard zone valve wiring via receiver |
| Underfloor heating zone control | ✓ | Via HCC100 multi-zone underfloor heating controller (sold separately) |
| Honeywell Home evohome | ✓ | Thermostat only — the DT4R thermostat integrates as a zone thermostat within evohome. The included relay receiver is not evohome-compatible; a BDR91A (sold separately) is required to connect the relay to evohome |
| Solid fuel boiler | ✓ | On/off demand; boiler must accept an external thermostat input |
| Direct 240V electric heating | ✗ | Not compatible — Resideo explicitly states "not with electric heating / 240V"; use wired DT4 (non-R) |
| OpenTherm® modulating control | ✗ | On/Off model only — for modulating control specify DT4R modulating variants (YT43 series) |
Technical Specifications
| Manufacturer | Resideo (Honeywell Home) |
| Model | DT4R |
| SKU / MPN | YT42WRFT20 |
| Colour | White |
| Control Mode | On/Off |
| Radio Frequency | 868.0–868.6 MHz ISM band |
| RF Range (max) | 30 m in typical residential building |
| RF Protocol | Ramses II / Ramses III |
| Thermostat Power | 2 × AA batteries (included) |
| Battery Life | Up to 1.5 years |
| Receiver Power Supply | 230V AC mains |
| Appliance Voltage (Switched) | 24–230V AC |
| Max Setpoint | 35°C |
| Operating Temperature | 0°C to 40°C |
| Temperature Sensor | 10kΩ @ 25°C NTC thermistor |
| Control Algorithm | Fuzzy logic |
| Display Type | LED segment (auto-off) |
| ErP Classification | Class IV (+2%) |
| Approvals | EMC 2014/30/EU · LVD 2014/35/EU · R&TTE 1995/5/EC |
| Display Indicators | Heat, Cool, Wireless signal, Eco, Off, Low battery, Warning |
✓ Drop-in replacement for DT92 / DT92E / DT92E1000: The DT4R uses the Ramses II RF protocol and is fully backwards compatible with existing Honeywell Home RF receivers. In most cases the existing receiver can be retained and the DT4R thermostat simply bound to it — the spare receiver from the pack is not required.
ℹ️ On/Off only — not suitable for direct electric heating or OpenTherm® modulating: This model switches a 24–230V on/off demand signal and cannot modulate heat output. For OpenTherm® modulating control, specify the DT4R modulating range (YT43MRFWT30 white · YT43MRFBT32 black · YT43MRFGT31 grey). For 240V direct electric heating, a wired DT4 variant is required.
Frequently Asked Questions
Does this come with a receiver?
Yes. The YT42WRFT20 is supplied as a complete pack including a wireless relay receiver that wires to the boiler or appliance. No separate receiver purchase is needed for a new standalone installation.
Can I use the BDR91A with this thermostat?
Yes. If you need the relay to connect to evohome or other home automation and heating control systems, the Honeywell Home BDR91A is compatible with the DT4R thermostat and is available to purchase separately. The relay receiver included in this pack is for standalone boiler switching only and is not evohome-compatible.
Will this work with my evohome system?
Partially. The DT4R thermostat unit can be integrated as a zone thermostat within an existing Honeywell Home evohome multi-zone system. However, the relay receiver included in this pack is not compatible with evohome — it can only be used for standalone boiler switching. To connect the relay to evohome or other home automation and heating control systems, the Honeywell Home BDR91A wireless relay box is required and is available to purchase separately.
Is it a direct replacement for the DT92E?
Yes. Resideo markets the DT4R as the direct successor to the DT92, DT92E, and DT92E1000. Ramses II compatibility means the thermostat will pair with receivers originally installed for those models in most cases.
Can I use it with a heat pump?
Yes, for heat pumps that accept a simple on/off 24–230V switching signal. It is not suitable for heat pumps requiring modulating or OpenTherm® communication — for those, specify the DT4R modulating variants (YT43 series).
Are other colours available?
Yes. The DT4R on/off wireless range is available in White (YT42WRFT20), Grey (YT42GRFT21), and Black (YT42BRFT22). Modulating wireless variants are available in the same three colours (YT43 series).
