Brink Renovent Excellent

Modbus RTU

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Last updated: 03. 2026

Brink Climate Systems

The Brink Renovent Excellent is a residential heat recovery ventilation unit (HRA) available in 300, 400 and 450 m3/h variants. It connects to TapHome via Modbus RTU over RS-485 using the built-in UWA2-B control PCB (standard version) or the UWA2-E extension PCB (Plus version). No additional gateway or adapter module is required.

The TapHome template provides ventilation speed control with preset modes (Away, Night, Boost) and custom flow rate, two temperature sensors (outdoor supply and dwelling extract air), filter status monitoring with reset capability, and bypass/imbalance configuration via service actions. Thirteen module-level service attributes expose additional diagnostics including airflow rates, pressures, preheater status, and the current Modbus slave address.

Hardware connection

RS-485 wiring

The Modbus RS-485 connection is on connector X15 of the UWA2-B PCB (standard version). On Plus models with UWA2-E extension PCB, use connector X06 on the UWA2-E board instead.

Brink UWA2-B PCB — RS-485 connector X15 wiring for standard models

On Plus models with the UWA2-E extension board, the RS-485 connection is on connector X06 of the UWA2-E PCB. The UWA2-B and UWA2-E boards are connected together via jumpers X12, X121 and X122:

Brink UWA2-E Plus PCB — RS-485 connector X06 wiring for Plus models

Connect the RS-485 bus to connector X15 (or X06 on Plus models):

RS485_A → A+/D+ on TapHome RS-485
RS485_B → B-/D- on TapHome RS-485
RS485_ground → GND on TapHome power supply

Important — Termination resistor
The UWA2-B PCB has a removable termination resistor at X12. If the Brink unit is not the last device on the RS-485 bus, remove the X12 terminator. On Plus models, the UWA2-E PCB has terminator X07 — remove it if not end-of-bus; in that case jumpers X12, X121 and X122 must be placed on the UWA2-B board.

Important — Safety
Always disconnect the appliance from mains power before working on the RS-485 wiring. Pull the power plug before opening the unit.

Technical specifications

Protocol: Modbus RTU Slave, RS-485
Baud rate: 19200 (factory default), configurable: 1200–115200
Parity: Even (factory default), configurable: None / Even / Odd
Stop bits: 1
Data bits: 8
Slave address: 20 (factory default), configurable: 1–247
Required firmware: UWA control PCB software version S1.06.06 or later

The TapHome template uses 9600 baud and slave ID 1 by default. Adjust either the Brink unit settings (Step 14.2–14.3) or the TapHome module connection settings to match.

Configuration

Enabling Modbus communication

Modbus must be enabled and configured on the Brink unit via the touchscreen display or Brink user interface. Navigate to the communication settings (Step 14):

Step 14.1 — Bus connection type: Set to ModBus (factory default is already ModBus)
Step 14.2 — Slave address: Change from default 20 to the desired address (e.g. 1 to match the TapHome template default)
Step 14.3 — Baud rate: Set to 9600 to match TapHome (factory default is 19200)
Step 14.4 — Parity: Keep as Even (matches TapHome default)

After configuring the Brink unit, set the same parameters in TapHome when importing the template: slave ID, baud rate (9600), parity (Even), 1 stop bit, 8 data bits.

Switching to Modbus control mode

By default, the Brink unit is controlled by its own settings (Brink mode). To control ventilation via TapHome, use the Set Control Mode service action on the module:

Modbus (4): Ventilation flow controlled via Modbus commands from TapHome
Brink (0): Flow control per Brink appliance settings (default)

Alternatively, register H:8000 can be set to 2 (flow rate control) to enable Modbus flow commands. The template uses register H:6012 for this purpose.

If the Brink HRA has been disconnected from mains power, the remote control registers (8000–8011) and the desired air flows must be set again.

Cascaded Brink appliances

If multiple Brink HRA units are cascaded, the Modbus connection must be made to the Master appliance with the Plus PCB UWA2-E. Each unit on the bus requires a unique slave address.

Device capabilities

Temperature monitoring

The template provides two temperature sensors with automatic conversion from tenths of degrees:

Outdoor Supply Temperature (H:4008) — outdoor air temperature at the supply fan inlet
Extract Air Temperature (H:4009) — dwelling extract air temperature at the exhaust fan

Both sensors read signed Int16 values divided by 10 to produce degrees Celsius. Two additional temperature service attributes mirror these readings at the module level (Supply Temperature and Exhaust Temperature).

Ventilation speed control

Ventilation Speed is a write-only multi-value switch with three preset airflow modes:

Preset	Flow rate	Use case
Away	50 m3/h	Minimum ventilation when nobody is home
Night	125 m3/h	Reduced nighttime ventilation
Boost	250 m3/h	Maximum ventilation for cooking, showering

For precise control, the Set Custom Flow Rate service action writes any value between 50 and 300 m3/h directly to register H:6000.

Filter monitoring

Filter Status (H:4039) shows the current filter condition:

OK — filter is clean
Polluted — filter needs replacement or cleaning

The device-level Reset Filter Warning service action writes to H:6006 to clear the filter dirty indicator after replacing or cleaning the filter.

Imbalance control

Imbalance Allowed (H:4015 read / H:6003 write) enables or disables supply/exhaust airflow imbalance. When enabled, the supply and exhaust fans can run at different speeds. The module-level Set Imbalance Offset Supply service action adjusts the supply airflow offset (-15% to +15%) for fine-tuning the balance.

Module-level service attributes

The template exposes 13 service attributes for comprehensive monitoring:

Attribute	Register	Description
Supply Temperature	H:4008	Outdoor supply air temperature (°C)
Exhaust Temperature	H:4009	Dwelling extract air temperature (°C)
Supply Pressure	H:4011	Supply air pressure (Pa)
Exhaust Pressure	H:4010	Exhaust air pressure (Pa)
Supply Airflow	H:4028	Measured supply air volume (m3/h)
Exhaust Airflow	H:4027	Measured exhaust air volume (m3/h)
Preheater State	H:4036	0=Initialization, 1=Inactive, 2=Active, 3=Test
Preheater Power	H:4038	Preheater output capacity (0–100%)
Filter Status	H:4039	0=OK, 1=Polluted
Imbalance Allowed	H:4015	0=Permitted, 1=Not permitted
Imbalance Offset Supply	H:4021	Supply airflow offset (%)
Bypass Mode	H:4030	0=Auto, 1=Closed, 2=Open
Modbus Slave Address	H:999	Current slave address

Module-level service actions

Four service actions provide configuration control:

Set Bypass Mode — switches between Automatic, Closed and Open bypass operation (H:6005)
Set Imbalance Offset Supply — adjusts supply airflow offset from -15% to +15% (H:6004)
Reset Filter Warning — clears the filter dirty indicator (H:6006)
Set Control Mode — switches between Brink (0) and Modbus (4) ventilation control (H:6012)

Additional capabilities

The Brink Renovent Excellent exposes over 100 additional Modbus registers not implemented in the current template. These include fan RPM readings, humidity sensors (supply and exhaust), CO2 sensor values (up to 4 sensors), frost protection status with 16-state machine, bypass valve position, geo-heat exchanger control, NTC temperature sensors, operating time counters, serial number readback, and the remote control registers (H:8000–8011) for switch position and standby control. Filter warning interval (1–365 days), bypass temperature thresholds, and digital/analogue input configuration are also available. These can be added in a future template update.

The remote control register H:8001 provides an alternative way to set ventilation modes using named presets (Holiday, Low, Normal, High) instead of direct flow rate values. This requires setting H:8000 to 1 (switch control mode).

Troubleshooting

No Modbus communication

Check RS-485 cables:
- RS485_A correctly connected to A+/D+ on TapHome
- RS485_B correctly connected to B-/D- on TapHome
- GND connected between the Brink unit and TapHome power supply
Verify the Modbus slave address matches between the Brink unit (Step 14.2) and TapHome template
Confirm baud rate and parity match — TapHome template defaults to 9600 baud, Even parity; the Brink factory default is 19200 baud, Even parity
Check that Step 14.1 is set to ModBus (not OFF or InternalBus)
Verify firmware version is S1.06.06 or later — older firmware may not support external Modbus
Check the termination resistor (X12 on UWA2-B, X07 on UWA2-E) — only the last device on the bus should have it

Ventilation speed not changing

Verify the control mode is set to Modbus (4) via the Set Control Mode service action
If using direct flow presets (H:6000), ensure the value is within the valid range for the HRA model (50–300 m3/h for most models)
After a power outage, registers 8000–8011 reset — the control mode and desired flow must be set again

Incorrect temperature readings

Temperature registers return values in tenths of degrees — a reading of 215 means 21.5°C
If readings show 0 or -32768, the sensor may be disconnected or faulty
H:4008 measures outdoor supply air; H:4009 measures dwelling extract air — verify the expected sensor

Filter warning not clearing

Use the Reset Filter Warning service action on the Filter Status device
If the reset fails, try the module-level Reset Filter Warning service action (writes to H:6006)
Physically replace or clean the filter before resetting — the warning will return if the filter is still dirty

Available devices

Brink Renovent Excellent Module

Service Attributes

Preheater State	Frost protection preheater status — Initialization, Inactive, Active, or Test mode
Preheater Power	Preheater output capacity as percentage (0–100%)
Filter Status
Imbalance Allowed
Imbalance Offset Supply	Supply airflow offset percentage for imbalance correction
Bypass Mode	Current bypass valve mode — Auto, Closed, or Open
Modbus Slave Address
Exhaust Airflow	Measured exhaust air volume flow rate in m3/h
Supply Airflow	Measured supply air volume flow rate in m3/h
Exhaust Temperature
Supply Temperature
Exhaust Pressure	Exhaust air pressure in Pascal
Supply Pressure	Supply air pressure in Pascal

Service Actions

Set Imbalance Offset Supply

Set Bypass Mode

Reset Filter Warning

Set Control Mode

Renovent Excellent

Service Attributes

Stav predhrievača [0: Inicializácia/1:Neaktívny/2: Aktívny/3:Testovací režim]

modbusr(H,4036,int16);

Výkon predhrievača [%]

modbusr(H,4038,int16);

Stav filtra

var state := modbusr(H,4039,int16);
return(switch(todouble(state), 0, "ok", "polluted"))

Nerovnováha povolená [0-on;1-off]

modbusr(H,4015,uint16)

Posun nerovnováhy pri prívode [%]

modbusr(H,4021, int16)

Režim obtoku [0 - auto; 1 - zatvoreny; 2 - otvoreny]

modbusr(H,4030,int16)

Adresa Slave Modbus

modbusr(H,999,int16)

(namerana hodnota) aktuálna hodnota prietoku výfukového vyduchu [m3/h]

MODBUSR(H, 4027, UInt16)

(namerana hodnota) aktuálna hodnota privádzaného vzduchu [m3/h]

MODBUSR(H, 4028, UInt16)

snímač teploty ventilátora odsávania [C]

MODBUSR(H, 4009, Int16) / 10

snímač teploty ventilátora prívodu [C]

MODBUSR(H, 4008, uInt16) / 10

aktuálny tlak odsávania [Pa]

MODBUSR(H, 4010, Int16)

aktualny tlak nasavania [PA]

MODBUSR(H, 4011, Int16)

Service Actions

Nastavenie posunu nerovnováhy pri prívode

Parameters: Posun nerovnováhy pri prívode [%] (-15–15 per)

modbusw(H,6004,int16,per);

Nastavenie režimu obtoku

Parameters: Parameter3


modbusw(H,6005,int16, isonv);

Vynulovanie hlásenia filtra

modbusw(h, 6006, int16,0)

Zmena rezimu ovladania (modbus/brink)

Parameters: Parameter2

if cont=4
MODBUSW(H,6012,int16,4);
else
MODBUSW(H,6012,int16,0);
end

Filter Status Multi-value Switch Read-only

Filter condition indicator — OK (clean) or Polluted (dirty), with service action to reset the filter warning

Values / States: OK · Znecisteny

Service Actions

Reset Filter Warning

Imbalance Allowed Switch

Enables or disables supply/exhaust airflow imbalance — when enabled, supply and exhaust fans can run at different speeds

Outdoor Supply Temperature Temperature Sensor Read-only

Outdoor air temperature measured at the supply fan inlet

Extract Air Temperature Temperature Sensor Read-only

Dwelling extract air temperature measured at the exhaust fan

Ventilation Speed Multi-value Switch

Ventilation airflow preset selector — Away (50 m3/h), Night (125 m3/h), or Boost (250 m3/h), with service action for custom flow rate

Int16 Unit: m3/h numeric

Values / States: Away · Night · Boost

Service Actions

Set Custom Flow Rate

Ventilation Speed

Write switch state

if Mu = 0
 MODBUSW(H, 6000, Int16, 50);
elseif Mu = 1
 MODBUSW(H, 6000, Int16, 125);
elseif Mu = 2
 MODBUSW(H, 6000, Int16, 200);
elseif Mu = 3
 MODBUSW(H, 6000, Int16, 250);
elseif Mu = 4
 MODBUSW(H, 6000, Int16, 250);
else
END

Service Actions

Požadované nastavenie rýchlosti prietoku

Parameters: Rychlost [50-300] (50–300 v)

MODBUSW(SH, 6000, Int16, v);

Connection: Modbus RTU • 9600 baud• 8E1 • Slave ID: $[SlaveId]

Possible improvements (21)

H:8000 Modbus Control Enable — 0=Modbus control off, 1=Switch control, 2=Flow rate control. Must be set before flow commands via H:8001/8002 take effect. Template uses H:6012 for control mode instead
H:8001 Switch Position — 0=Holiday, 1=Low, 2=Normal, 3=High. Alternative to direct flow preset writing. Requires H:8000=1
H:8002 Desired Flow Rate — Direct flow rate in m3/h. Requires H:8000=2. Alternative to H:6000 used by template
H:8003 Request Standby — 0=No action, 1=Set standby, 2=Set normal mode. Puts entire unit in standby
H:8010 Reset Filter Warning (remote) — Write 1 to reset. Alternative to H:6006 used by template. Read returns 1=executed, 0xFF=failed
H:8011 Appliance Reset — Write 1 to reset appliance. Read returns 1=executed, 0xFF=failed
H:4020 HRA Active Function — Current operating mode: 0=Standby, 4=Manual, 5=Holiday, 6=Night Ventilation, 7=Party, 8=Bypass Boost, 9=Normal Boost, 10=Auto CO2, 12=Auto Modbus, etc.
H:4022 Ventilation Mode — 0=Holiday, 1=Low, 2=Normal, 3=High, 4=Auto. Current ventilation mode — useful for readback
H:4050 Bypass Status — 0=Initialize, 1=Open, 2=Close, 3=Open, 4=Closed. Actual bypass valve position
H:4060 Preheater Status — 0=Initialize, 1=Inactive, 2=Active, 3=Test mode. Already partially exposed via module service attribute
H:4070 Frost Status — 16-state frost protection status: No Frost, Ice Detected, Heating, Fan Off, etc.
H:4081 NTC1 Temperature — Additional temperature sensor, tenths of degrees. Available on UWA2-B PCB
H:4082 NTC2 Temperature — Additional temperature sensor, tenths of degrees. Available on UWA2-B PCB
H:4083 RHT Sensor Humidity — Relative humidity in tenths of percent (0–100.0%). Requires RHT sensor mode enabled
H:4201 CO2 Sensor 1 Value — CO2 level in ppm. Up to 4 CO2 sensors supported (H:4201/4203/4205/4207)
H:6100 Bypass Mode (config) — 0=Automatic, 1=Bypass closed, 2=Bypass open. Template uses H:6005 for bypass write which is listed as 'Bypass mode' in official docs at H:6100
H:6120 Days Before Filter Warning — 1–365 days, default 90. Configures when filter warning triggers
H:4034 Supply Fan Speed — Supply fan speed in RPM
H:4044 Exhaust Fan Speed — Exhaust fan speed in RPM
H:4037 Supply Fan Humidity — Relative humidity at supply fan in tenths of percent (0–100.0%)
H:4047 Exhaust Fan Humidity — Relative humidity at exhaust fan in tenths of percent (0–100.0%)

Download Template

Sources

Brink Modbus UWA2-B/UWA2-E Installation Regulations (614882-D)
www.brinkclimatesystems.nl 2026-03-20
PDF
openHAB Community — Brink Renovent Excellent 300 Modbus Integration
community.openhab.org 2026-03-20