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Honeywell Home BDR91A Wireless Relay Box | BDR91A1000 | evohome Compatible RF Boiler Receiver
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Honeywell Home BDR91A Wireless Relay Box | BDR91A1000 | evohome Compatible RF Boiler Receiver

Honeywell Home BDR91A Wireless Relay Box | BDR91A1000 | evohome Compatible RF Boiler Receiver

Honeywell Home Wireless RF 868 MHz evohome Compatible 5A Switching 230V or Volt-Free Ramses II Protocol
MPN BDR91A1000
Model Name BDR91A
EAN 5025121385114
Max Switching Current 5A
Supply Voltage 230V AC mains (permanent)

The Honeywell Home BDR91A is a mains-powered wireless relay module that acts as the switching interface between a Honeywell Home RF heating controller and a boiler, pump, motorised valve, electric towel rail, or other heating appliance. It receives demand signals over the 868 MHz Ramses II RF protocol and switches the connected load on and off accordingly, replacing the need for a direct wired link between thermostat and appliance. The BDR91A is compatible with the full range of Honeywell Home 868 MHz wireless controls including evohome, DT4R, DT92E, CM927, CM921, and the Sundial RF² range, making it the correct receiver to specify when evohome integration or compatibility with home automation and heating control systems is required. It supports both 230V switching and volt-free (potential-free) switching up to 5A, covering the majority of residential and light commercial heating applications. A binding procedure is required on installation to pair the BDR91A with the controlling device.

Key Features
  • evohome compatible — the correct receiver to use when connecting to the Honeywell Home evohome system or home automation platforms
  • 868 MHz Ramses II RF protocol — compatible with the full range of Honeywell Home wireless heating controls
  • 230V switched output or volt-free (potential-free) switching — suits boilers, pumps, motorised valves, electric towel rails and more
  • 5A maximum switching current — covers the vast majority of residential heating components
  • Permanent 230V mains supply — no batteries required; always on and ready to receive RF commands
  • LED status indication — green LED confirms relay state; red LED indicates RF communication loss
  • Failsafe mode — if RF communication is lost, relay operates in a configurable failsafe state
  • Binding procedure — pairs the relay to the specific controller during commissioning; one-to-one relationship
  • Install at least 30cm from metal objects — including wall boxes and boiler housing, for best RF performance
  • Compatible with DT4R, DT92E, CM927, CM921, evohome, Sundial RF² and other Honeywell Home 868 MHz products
✓ Required for evohome and home automation integration: The BDR91A is the relay module needed when the switching function must be managed by the Honeywell Home evohome controller or integrated into a broader home automation or heating control system. It is also the correct replacement for the DT4R pack receiver in any installation requiring evohome compatibility.
Compatible Honeywell Home Controllers
Controller / System Compatible? Notes
Honeywell Home evohome ✓ Primary use case — evohome controller manages boiler demand via BDR91A
DT4R wireless room thermostat (YT42WRFT20 / YT42GRFT21 / YT42BRFT22) ✓ Replaces the basic relay included in the DT4R pack for evohome-compatible installations
DT92E / DT92E1000 ✓ Standard pairing for the DT92E wireless thermostat range
CM927 / CM921 wireless programmable thermostat ✓ Fully compatible; standard pairing for CM927 / CM921 installations
Sundial RF² range ✓ Compatible with the complete Sundial RF² product family
HCW80 / T87RF wireless controls ✓ Confirmed compatible with Honeywell Home 868 MHz Ramses II devices
Heat pump (on/off demand) ✗ The BDR91A is not suitable for heat pump applications — specify the BDR91T1004 (post-2021, with house symbol) for heat pump installations
Non-Honeywell / different RF frequency controllers ✗ The BDR91A will only communicate with Honeywell Home 868 MHz Ramses II devices
Technical Specifications
Manufacturer Resideo (Honeywell Home)
Model BDR91A
MPN BDR91A1000
EAN 5025121385114
Radio Frequency 868 MHz ISM band
RF Protocol Ramses II
Mains Supply 230V AC 50–60Hz (permanent)
Max Switching Current 5A
Switching Type 230V switched or volt-free (potential-free)
Wire Cross-Section 1.5–2.5mm²
LED Indicators Green (relay active) · Red (RF communication lost)
Failsafe Configurable via installer mode
ℹ️ Binding required: The BDR91A must be bound (paired) to the controlling device before use. If replacing an existing unit or adding to an existing system, reset stored binding data first and follow the binding procedure in the installation guide. The BDR91A can only communicate with the single device it is bound to.
⚠️ Not suitable for heat pumps: The BDR91A does not support heat pump applications. For heat pump installations using Honeywell Home RF controls, the BDR91T1004 (post-2021 version, identifiable by the house symbol on the front cover) is required instead.
Frequently Asked Questions
What is the difference between the BDR91A and the receiver included with the DT4R pack?
The relay receiver supplied with the DT4R wireless thermostat pack (YT42WRFT20 etc.) is a basic relay for standalone boiler switching only and is not compatible with the evohome system or other home automation and heating control platforms. The BDR91A is the correct receiver to specify when evohome integration is needed, or when the relay must be managed by a central heating controller rather than the thermostat alone.
Can I use one BDR91A with multiple thermostats or controllers?
No. The BDR91A operates on a one-to-one basis — it can only be bound to a single controlling device at a time. For multi-zone installations, a separate BDR91A is required for each zone or appliance being switched.
Does the BDR91A work with the DT4R thermostat?
Yes. The DT4R thermostat is compatible with the BDR91A via the Ramses II RF protocol. This combination is the correct pairing for any DT4R installation that also needs evohome compatibility or integration with a home automation system.
Does it need batteries?
No. The BDR91A requires a permanent 230V AC mains supply. It must be wired into the mains at installation — it cannot operate on battery power.
What does the red LED indicate?
A red LED indicates that RF communication with the bound controller has been lost. In this state, the relay enters failsafe mode as configured during installation. If the red LED appears during normal operation, check for obstructions between the BDR91A and the controller, and ensure the unit is not mounted on or near metal objects.
Can it switch volt-free (potential-free) contacts?
Yes. In addition to 230V switching, the BDR91A supports volt-free (potential-free) switching, making it suitable for applications where only a clean contact closure is required rather than a mains-switched output — for example, certain boiler demand inputs and zone valve actuators.
$31.18

Original: $89.08

-65%
Honeywell Home BDR91A Wireless Relay Box | BDR91A1000 | evohome Compatible RF Boiler Receiver—

$89.08

$31.18

Honeywell Home BDR91A Wireless Relay Box | BDR91A1000 | evohome Compatible RF Boiler Receiver

Honeywell Home Wireless RF 868 MHz evohome Compatible 5A Switching 230V or Volt-Free Ramses II Protocol
MPN BDR91A1000
Model Name BDR91A
EAN 5025121385114
Max Switching Current 5A
Supply Voltage 230V AC mains (permanent)

The Honeywell Home BDR91A is a mains-powered wireless relay module that acts as the switching interface between a Honeywell Home RF heating controller and a boiler, pump, motorised valve, electric towel rail, or other heating appliance. It receives demand signals over the 868 MHz Ramses II RF protocol and switches the connected load on and off accordingly, replacing the need for a direct wired link between thermostat and appliance. The BDR91A is compatible with the full range of Honeywell Home 868 MHz wireless controls including evohome, DT4R, DT92E, CM927, CM921, and the Sundial RF² range, making it the correct receiver to specify when evohome integration or compatibility with home automation and heating control systems is required. It supports both 230V switching and volt-free (potential-free) switching up to 5A, covering the majority of residential and light commercial heating applications. A binding procedure is required on installation to pair the BDR91A with the controlling device.

Key Features
  • evohome compatible — the correct receiver to use when connecting to the Honeywell Home evohome system or home automation platforms
  • 868 MHz Ramses II RF protocol — compatible with the full range of Honeywell Home wireless heating controls
  • 230V switched output or volt-free (potential-free) switching — suits boilers, pumps, motorised valves, electric towel rails and more
  • 5A maximum switching current — covers the vast majority of residential heating components
  • Permanent 230V mains supply — no batteries required; always on and ready to receive RF commands
  • LED status indication — green LED confirms relay state; red LED indicates RF communication loss
  • Failsafe mode — if RF communication is lost, relay operates in a configurable failsafe state
  • Binding procedure — pairs the relay to the specific controller during commissioning; one-to-one relationship
  • Install at least 30cm from metal objects — including wall boxes and boiler housing, for best RF performance
  • Compatible with DT4R, DT92E, CM927, CM921, evohome, Sundial RF² and other Honeywell Home 868 MHz products
✓ Required for evohome and home automation integration: The BDR91A is the relay module needed when the switching function must be managed by the Honeywell Home evohome controller or integrated into a broader home automation or heating control system. It is also the correct replacement for the DT4R pack receiver in any installation requiring evohome compatibility.
Compatible Honeywell Home Controllers
Controller / System Compatible? Notes
Honeywell Home evohome ✓ Primary use case — evohome controller manages boiler demand via BDR91A
DT4R wireless room thermostat (YT42WRFT20 / YT42GRFT21 / YT42BRFT22) ✓ Replaces the basic relay included in the DT4R pack for evohome-compatible installations
DT92E / DT92E1000 ✓ Standard pairing for the DT92E wireless thermostat range
CM927 / CM921 wireless programmable thermostat ✓ Fully compatible; standard pairing for CM927 / CM921 installations
Sundial RF² range ✓ Compatible with the complete Sundial RF² product family
HCW80 / T87RF wireless controls ✓ Confirmed compatible with Honeywell Home 868 MHz Ramses II devices
Heat pump (on/off demand) ✗ The BDR91A is not suitable for heat pump applications — specify the BDR91T1004 (post-2021, with house symbol) for heat pump installations
Non-Honeywell / different RF frequency controllers ✗ The BDR91A will only communicate with Honeywell Home 868 MHz Ramses II devices
Technical Specifications
Manufacturer Resideo (Honeywell Home)
Model BDR91A
MPN BDR91A1000
EAN 5025121385114
Radio Frequency 868 MHz ISM band
RF Protocol Ramses II
Mains Supply 230V AC 50–60Hz (permanent)
Max Switching Current 5A
Switching Type 230V switched or volt-free (potential-free)
Wire Cross-Section 1.5–2.5mm²
LED Indicators Green (relay active) · Red (RF communication lost)
Failsafe Configurable via installer mode
ℹ️ Binding required: The BDR91A must be bound (paired) to the controlling device before use. If replacing an existing unit or adding to an existing system, reset stored binding data first and follow the binding procedure in the installation guide. The BDR91A can only communicate with the single device it is bound to.
⚠️ Not suitable for heat pumps: The BDR91A does not support heat pump applications. For heat pump installations using Honeywell Home RF controls, the BDR91T1004 (post-2021 version, identifiable by the house symbol on the front cover) is required instead.
Frequently Asked Questions
What is the difference between the BDR91A and the receiver included with the DT4R pack?
The relay receiver supplied with the DT4R wireless thermostat pack (YT42WRFT20 etc.) is a basic relay for standalone boiler switching only and is not compatible with the evohome system or other home automation and heating control platforms. The BDR91A is the correct receiver to specify when evohome integration is needed, or when the relay must be managed by a central heating controller rather than the thermostat alone.
Can I use one BDR91A with multiple thermostats or controllers?
No. The BDR91A operates on a one-to-one basis — it can only be bound to a single controlling device at a time. For multi-zone installations, a separate BDR91A is required for each zone or appliance being switched.
Does the BDR91A work with the DT4R thermostat?
Yes. The DT4R thermostat is compatible with the BDR91A via the Ramses II RF protocol. This combination is the correct pairing for any DT4R installation that also needs evohome compatibility or integration with a home automation system.
Does it need batteries?
No. The BDR91A requires a permanent 230V AC mains supply. It must be wired into the mains at installation — it cannot operate on battery power.
What does the red LED indicate?
A red LED indicates that RF communication with the bound controller has been lost. In this state, the relay enters failsafe mode as configured during installation. If the red LED appears during normal operation, check for obstructions between the BDR91A and the controller, and ensure the unit is not mounted on or near metal objects.
Can it switch volt-free (potential-free) contacts?
Yes. In addition to 230V switching, the BDR91A supports volt-free (potential-free) switching, making it suitable for applications where only a clean contact closure is required rather than a mains-switched output — for example, certain boiler demand inputs and zone valve actuators.

Product Information

Shipping & Returns

Description

Honeywell Home Wireless RF 868 MHz evohome Compatible 5A Switching 230V or Volt-Free Ramses II Protocol
MPN BDR91A1000
Model Name BDR91A
EAN 5025121385114
Max Switching Current 5A
Supply Voltage 230V AC mains (permanent)

The Honeywell Home BDR91A is a mains-powered wireless relay module that acts as the switching interface between a Honeywell Home RF heating controller and a boiler, pump, motorised valve, electric towel rail, or other heating appliance. It receives demand signals over the 868 MHz Ramses II RF protocol and switches the connected load on and off accordingly, replacing the need for a direct wired link between thermostat and appliance. The BDR91A is compatible with the full range of Honeywell Home 868 MHz wireless controls including evohome, DT4R, DT92E, CM927, CM921, and the Sundial RF² range, making it the correct receiver to specify when evohome integration or compatibility with home automation and heating control systems is required. It supports both 230V switching and volt-free (potential-free) switching up to 5A, covering the majority of residential and light commercial heating applications. A binding procedure is required on installation to pair the BDR91A with the controlling device.

Key Features
  • evohome compatible — the correct receiver to use when connecting to the Honeywell Home evohome system or home automation platforms
  • 868 MHz Ramses II RF protocol — compatible with the full range of Honeywell Home wireless heating controls
  • 230V switched output or volt-free (potential-free) switching — suits boilers, pumps, motorised valves, electric towel rails and more
  • 5A maximum switching current — covers the vast majority of residential heating components
  • Permanent 230V mains supply — no batteries required; always on and ready to receive RF commands
  • LED status indication — green LED confirms relay state; red LED indicates RF communication loss
  • Failsafe mode — if RF communication is lost, relay operates in a configurable failsafe state
  • Binding procedure — pairs the relay to the specific controller during commissioning; one-to-one relationship
  • Install at least 30cm from metal objects — including wall boxes and boiler housing, for best RF performance
  • Compatible with DT4R, DT92E, CM927, CM921, evohome, Sundial RF² and other Honeywell Home 868 MHz products
✓ Required for evohome and home automation integration: The BDR91A is the relay module needed when the switching function must be managed by the Honeywell Home evohome controller or integrated into a broader home automation or heating control system. It is also the correct replacement for the DT4R pack receiver in any installation requiring evohome compatibility.
Compatible Honeywell Home Controllers
Controller / System Compatible? Notes
Honeywell Home evohome ✓ Primary use case — evohome controller manages boiler demand via BDR91A
DT4R wireless room thermostat (YT42WRFT20 / YT42GRFT21 / YT42BRFT22) ✓ Replaces the basic relay included in the DT4R pack for evohome-compatible installations
DT92E / DT92E1000 ✓ Standard pairing for the DT92E wireless thermostat range
CM927 / CM921 wireless programmable thermostat ✓ Fully compatible; standard pairing for CM927 / CM921 installations
Sundial RF² range ✓ Compatible with the complete Sundial RF² product family
HCW80 / T87RF wireless controls ✓ Confirmed compatible with Honeywell Home 868 MHz Ramses II devices
Heat pump (on/off demand) ✗ The BDR91A is not suitable for heat pump applications — specify the BDR91T1004 (post-2021, with house symbol) for heat pump installations
Non-Honeywell / different RF frequency controllers ✗ The BDR91A will only communicate with Honeywell Home 868 MHz Ramses II devices
Technical Specifications
Manufacturer Resideo (Honeywell Home)
Model BDR91A
MPN BDR91A1000
EAN 5025121385114
Radio Frequency 868 MHz ISM band
RF Protocol Ramses II
Mains Supply 230V AC 50–60Hz (permanent)
Max Switching Current 5A
Switching Type 230V switched or volt-free (potential-free)
Wire Cross-Section 1.5–2.5mm²
LED Indicators Green (relay active) · Red (RF communication lost)
Failsafe Configurable via installer mode
ℹ️ Binding required: The BDR91A must be bound (paired) to the controlling device before use. If replacing an existing unit or adding to an existing system, reset stored binding data first and follow the binding procedure in the installation guide. The BDR91A can only communicate with the single device it is bound to.
⚠️ Not suitable for heat pumps: The BDR91A does not support heat pump applications. For heat pump installations using Honeywell Home RF controls, the BDR91T1004 (post-2021 version, identifiable by the house symbol on the front cover) is required instead.
Frequently Asked Questions
What is the difference between the BDR91A and the receiver included with the DT4R pack?
The relay receiver supplied with the DT4R wireless thermostat pack (YT42WRFT20 etc.) is a basic relay for standalone boiler switching only and is not compatible with the evohome system or other home automation and heating control platforms. The BDR91A is the correct receiver to specify when evohome integration is needed, or when the relay must be managed by a central heating controller rather than the thermostat alone.
Can I use one BDR91A with multiple thermostats or controllers?
No. The BDR91A operates on a one-to-one basis — it can only be bound to a single controlling device at a time. For multi-zone installations, a separate BDR91A is required for each zone or appliance being switched.
Does the BDR91A work with the DT4R thermostat?
Yes. The DT4R thermostat is compatible with the BDR91A via the Ramses II RF protocol. This combination is the correct pairing for any DT4R installation that also needs evohome compatibility or integration with a home automation system.
Does it need batteries?
No. The BDR91A requires a permanent 230V AC mains supply. It must be wired into the mains at installation — it cannot operate on battery power.
What does the red LED indicate?
A red LED indicates that RF communication with the bound controller has been lost. In this state, the relay enters failsafe mode as configured during installation. If the red LED appears during normal operation, check for obstructions between the BDR91A and the controller, and ensure the unit is not mounted on or near metal objects.
Can it switch volt-free (potential-free) contacts?
Yes. In addition to 230V switching, the BDR91A supports volt-free (potential-free) switching, making it suitable for applications where only a clean contact closure is required rather than a mains-switched output — for example, certain boiler demand inputs and zone valve actuators.