Komfovent Komfovent DOMEKT C8 Modbus TCP template

Komfovent DOMEKT C8

Controls and monitors Komfovent DOMEKT residential ventilation units via Modbus TCP

This template connects Komfovent DOMEKT C8 residential ventilation units to ModbusCloud via Modbus TCP. It reads supply, extract, outdoor, and return temperatures, fan intensities, humidity, filter status, and alarms. It also provides control over on/off state, operating modes, flow setpoints, and temperature setpoints across multiple ventilation profiles.

Protocol
Modbus TCP
Connection
Ethernet, Modbus TCP
Registers
37, read and write
Key readings
Supply/Extract/Outdoor/Return temperatures · Supply and Extract fan intensity · Panel 1 and Panel 2 humidity · Filter impurity level · Active alarms count · Heat exchanger and heater/cooler output
Available commands
ON/OFF, ECO, AUTO, and mode selection · Supply and Extract flow setpoints (Away/Normal/Intensive/Boost) · Temperature setpoints (Away/Normal/Intensive/Boost) · Temperature control mode and scheduler operation mode
Compatible models
DOMEKT C8
Last updated

Registers (37)

23 read, 18 write

NameUnitAccessAddress (Hidden until you enter your email)Function (hidden)Type (hidden)
Return water temperature°CRead
Current modeRead and write
Active alarms countcountRead
Supply temperature°CRead
ON/OFF statusRead and write
ECO modeRead and write
AUTO modeRead and write
Current supply fan intensivity%Read
Current extract fan intensivity%Read
Heat exchanger%Read
Panel 2 humidity%Read
Extract temperature°CRead
Filters Impurity%Read
Water cooler%Read
Electric heater%Read
Water heater%Read
DX unit%Read
Outdoor temperature°CRead
Panel 2 temperature°CRead
Panel 1 temperature°CRead
Panel 1 humidity%Read
Connected panelsRead
Sensor (B8)Read
Boost (Supply flow setpoint)Write
Boost (Temperature setpoint)°CWrite
Scheduler operation modeWrite
Temperature control modeWrite
Away (Supply flow setpoint)Write
Normal (Supply flow setpoint)Write
Intensive (Supply flow setpoint)Write
Away (Extract flow setpoint)Write
Normal (Extract flow setpoint)Write
Intensive (Extract flow setpoint)Write
Boost (Extract flow setpoint)Write
Intensive (Temperature setpoint)°CWrite
Away (Temperature setpoint)°CWrite
Normal (Temperature setpoint)°CWrite

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Number of installations (optional)

Use cases

  • Monitor supply, extract, outdoor, and return air temperatures on a live dashboard for residential ventilation clients.
  • Create alerts when filter impurity level exceeds a threshold so maintenance can be scheduled proactively.
  • Adjust Away, Normal, Intensive, and Boost flow setpoints remotely to match seasonal occupancy patterns.
  • Track active alarm counts and receive notifications when faults occur on the DOMEKT C8 unit.
  • Switch between ECO, AUTO, and manual operating modes from the cloud without on-site intervention.
  • Log humidity and fan intensity data over time to verify indoor air quality compliance.

Installation

  1. Connect the ModbusCloud Gateway to the same local network as the Komfovent DOMEKT C8, ensuring both devices can communicate over Modbus TCP on port 502.

  2. Verify that Modbus TCP is enabled on the DOMEKT C8 control panel and note the unit's IP address and Modbus slave ID.

  3. In the ModbusCloud portal, add a new device and import the Komfovent DOMEKT C8 template from the template library.

  4. Enter the IP address and slave ID of the DOMEKT C8 in the device configuration screen.

  5. Confirm that 32-bit flow setpoint registers (e.g. addresses 99, 101, 105, 107) are mapped as uint32 spanning two registers each, and that temperature registers are mapped as int16.

  6. Verify live data appears on the ModbusCloud dashboard by checking that temperature readings and fan intensity values update correctly.

Things to watch for

Flow setpoint values appear incorrect or extremely large. What is wrong?

The supply and extract flow setpoint registers are unsigned 32-bit integers that span two consecutive Modbus registers. Ensure the template maps these as uint32 with the correct register pair. Swapping the high and low words will produce invalid values.

Temperature readings show unexpected negative or zero values.

Temperature registers are signed 16-bit integers (int16) in degrees Celsius. Confirm the register data type is set to int16, not uint16. Also verify the correct Modbus slave ID and register addresses.

The gateway cannot connect to the DOMEKT C8 over Modbus TCP.

Check that Modbus TCP is enabled in the C8 control settings and that the unit's IP address is reachable from the gateway's network. The default Modbus TCP port is 502. Ensure no firewall or VLAN configuration is blocking traffic between the devices.

Humidity readings from Panel 1 or Panel 2 are not updating.

Humidity values require optional external sensors connected to the DOMEKT C8. If no humidity sensor is installed on a given panel, the register will return zero or a default value. Verify sensor wiring at the unit.

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