Vallox MV
Heat recovery ventilation unit that reports air temperatures, humidity, CO2 and faults and sets modes.
The Vallox MV is a heat recovery ventilation unit with MyVallox control that supplies fresh air and extracts stale air in homes and small buildings. This Modbus RTU template reads air temperatures, fan speed, humidity, CO2, filter time and faults, and lets you set the mode, boost timer, fan speeds, supply temperature and weekly schedule from ModbusCloud.
- Protocol
- Modbus RTU
- Connection
- RS485, 19200 baud
- Registers
- 320, read and write
- Brand
- Vallox
- Key readings
- Fan speed · Extract air temperature · Outdoor air temperature · Supply air temperature · Relative humidity · CO2 concentration · Filter remaining days · Critical fault
- Available commands
- Home, away or automatic · Unit on or off · Boost timer · Fan speed per mode · Supply temperature per mode · Weekly schedule
- Compatible models
- MyVallox MV · ValloPlus MV · MyVallox CFi · Vallox MV heat recovery ventilation units with MyVallox control (Modbus RTU) · MyVallox CFi units (airflow registers)
- Last updated
Registers (320)
320 read, 253 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Fan Speed | % | Read | |||
| Extract Air Temperature | K | Read | |||
| Exhaust Air Temperature | K | Read | |||
| Outdoor Air Temperature | K | Read | |||
| Supply Cell Air Temperature | K | Read | |||
| Supply Air Temperature | K | Read | |||
| Optional Sensor Temperature | K | Read | |||
| Relative Humidity | %RH | Read | |||
| CO2 Concentration | ppm | Read | |||
| Extract Fan Speed RPM | rpm | Read | |||
| Supply Fan Speed RPM | rpm | Read | |||
| Heat Exchanger State | Read | ||||
| Critical Fault Active | Read | ||||
| Filter Remaining Days | d | Read | |||
| Total Fault Count | Read | ||||
| RH Level | Read | ||||
| CO2 Level | Read | ||||
| Digital Input 1 | Read | ||||
| Digital Input 2 | Read | ||||
| Analog Control Input | % | Read | |||
| Multisensor CO2 Raw | Read | ||||
| Multisensor Temperature Raw | Read | ||||
| Multisensor Humidity Raw | Read | ||||
| Internal RH Sensor | %RH | Read | |||
| RH Sensor 0 | %RH | Read | |||
| RH Sensor 1 | %RH | Read | |||
| RH Sensor 2 | %RH | Read | |||
| RH Sensor 3 | %RH | Read | |||
| RH Sensor 4 | %RH | Read | |||
| RH Sensor 5 | %RH | Read | |||
| CO2 Sensor 0 | ppm | Read | |||
| CO2 Sensor 1 | ppm | Read | |||
| CO2 Sensor 2 | ppm | Read | |||
| CO2 Sensor 3 | ppm | Read | |||
| CO2 Sensor 4 | ppm | Read | |||
| CO2 Sensor 5 | ppm | Read | |||
| VOC Level | ppm | Read | |||
| VOC Sensor 0 | ppm | Read | |||
| VOC Sensor 1 | ppm | Read | |||
| VOC Sensor 2 | ppm | Read | |||
| VOC Sensor 3 | ppm | Read | |||
| Ventilation Profile | Read and write | ||||
| Unit On Off | Read and write | ||||
| Manual Defrosting | Read and write | ||||
| Boost Timer | min | Read and write | |||
| Custom Timer | min | Read and write | |||
| Programmable Input Timer | min | Read and write | |||
| Weekly Timer Enabled | Read and write | ||||
| Total Up Time Years | Read | ||||
| Total Up Time Hours | h | Read | |||
| Current Up Time | h | Read | |||
| Command | Read and write | ||||
| Earth Heat Radiator State | Read | ||||
| Clock Minute | min | Read and write | |||
| Clock Hour | h | Read and write | |||
| Date Day | Read and write | ||||
| Date Month | Read and write | ||||
| Date Year | Read and write | ||||
| Weekday | Read | ||||
| Gateway Address High | Read | ||||
| Gateway Address Low | Read | ||||
| Subnet Mask High | Read | ||||
| Subnet Mask Low | Read | ||||
| Cloud Connection Enabled | Read and write | ||||
| IP Address High | Read | ||||
| IP Address Low | Read | ||||
| Modbus Address | Read and write | ||||
| Modbus Baud Rate x100 | Read and write | ||||
| Modbus Frame | Read and write | ||||
| Extract Fan Balance | % | Read and write | |||
| Supply Fan Balance | % | Read and write | |||
| Custom Extract Fan Speed | % | Read and write | |||
| Custom Supply Fan Speed | % | Read and write | |||
| RH Threshold | % | Read and write | |||
| CO2 Threshold | ppm | Read and write | |||
| Programmable Input Supply Temperature | K | Read and write | |||
| Programmable Input Extract Fan Speed | % | Read and write | |||
| Programmable Input Supply Fan Speed | % | Read and write | |||
| Programmable Input Time | min | Read and write | |||
| Custom Supply Temperature | K | Read and write | |||
| Away RH Control | Read and write | ||||
| Away CO2 Control | Read and write | ||||
| Away Fan Speed Setting | % | Read and write | |||
| Away Supply Temperature Setting | K | Read and write | |||
| Home RH Control | Read and write | ||||
| Home CO2 Control | Read and write | ||||
| Home Fan Speed Setting | % | Read and write | |||
| Home Supply Temperature Setting | K | Read and write | |||
| Boost RH Control | Read and write | ||||
| Boost CO2 Control | Read and write | ||||
| Boost Fan Speed Setting | % | Read and write | |||
| Boost Supply Temperature Setting | K | Read and write | |||
| Relay Mode | Read and write | ||||
| Digital Input 1 Mode | Read and write | ||||
| Digital Input 2 Mode | Read and write | ||||
| Analog Input Mode | Read and write | ||||
| MLV Supply Lower Limit | K | Read and write | |||
| MLV Control Type | Read and write | ||||
| MLV Summer Setpoint | K | Read and write | |||
| MLV Modes | Read and write | ||||
| MLV Winter Setpoint | K | Read and write | |||
| Filter Change Interval | d | Read and write | |||
| Heat Recovery Cell Type | Read and write | ||||
| Extra Heater Type | Read and write | ||||
| Post Heater Type | Read and write | ||||
| RH Level Mode | Read and write | ||||
| Boost Time | min | Read and write | |||
| Custom Time | min | Read and write | |||
| Filter Changed Day | d | Read and write | |||
| Filter Changed Month | Read and write | ||||
| Filter Changed Year | Read and write | ||||
| Temperature Control Method | Read and write | ||||
| Partial Bypass | Read and write | ||||
| Bypass Locked | Read and write | ||||
| Optional Sensor Mode | Read and write | ||||
| Post Heater Winter Limit | K | Read and write | |||
| Dew Point Limit In Use | Read and write | ||||
| Access Level | Read and write | ||||
| Parental Control Enabled | Read and write | ||||
| Boost Timer Enabled | Read and write | ||||
| Custom Timer Enabled | Read and write | ||||
| Automatic Summer Time | Read and write | ||||
| 12 Hour Clock | Read and write | ||||
| Programmable Input Timer Enabled | Read and write | ||||
| CFi Limiter | Read and write | ||||
| CFi Limiter Active | Read | ||||
| CFi Supply Fan Load | Read | ||||
| CFi Extract Fan Load | Read | ||||
| Fault 1 Code | Read | ||||
| Fault 1 State | Read and write | ||||
| Fault 2 Code | Read | ||||
| Fault 2 State | Read and write | ||||
| Fault 3 Code | Read | ||||
| Fault 3 State | Read and write | ||||
| Fault 4 Code | Read | ||||
| Fault 4 State | Read and write | ||||
| Fault 5 Code | Read | ||||
| Fault 5 State | Read and write | ||||
| Fault 6 Code | Read | ||||
| Fault 6 State | Read and write | ||||
| Fault 7 Code | Read | ||||
| Fault 7 State | Read and write | ||||
| Fault 8 Code | Read | ||||
| Fault 8 State | Read and write | ||||
| Fault 9 Code | Read | ||||
| Fault 9 State | Read and write | ||||
| Fault 10 Code | Read | ||||
| Fault 10 State | Read and write | ||||
| Schedule Monday 00:00 | Read and write | ||||
| Schedule Monday 01:00 | Read and write | ||||
| Schedule Monday 02:00 | Read and write | ||||
| Schedule Monday 03:00 | Read and write | ||||
| Schedule Monday 04:00 | Read and write | ||||
| Schedule Monday 05:00 | Read and write | ||||
| Schedule Monday 06:00 | Read and write | ||||
| Schedule Monday 07:00 | Read and write | ||||
| Schedule Monday 08:00 | Read and write | ||||
| Schedule Monday 09:00 | Read and write | ||||
| Schedule Monday 10:00 | Read and write | ||||
| Schedule Monday 11:00 | Read and write | ||||
| Schedule Monday 12:00 | Read and write | ||||
| Schedule Monday 13:00 | Read and write | ||||
| Schedule Monday 14:00 | Read and write | ||||
| Schedule Monday 15:00 | Read and write | ||||
| Schedule Monday 16:00 | Read and write | ||||
| Schedule Monday 17:00 | Read and write | ||||
| Schedule Monday 18:00 | Read and write | ||||
| Schedule Monday 19:00 | Read and write | ||||
| Schedule Monday 20:00 | Read and write | ||||
| Schedule Monday 21:00 | Read and write | ||||
| Schedule Monday 22:00 | Read and write | ||||
| Schedule Monday 23:00 | Read and write | ||||
| Schedule Tuesday 00:00 | Read and write | ||||
| Schedule Tuesday 01:00 | Read and write | ||||
| Schedule Tuesday 02:00 | Read and write | ||||
| Schedule Tuesday 03:00 | Read and write | ||||
| Schedule Tuesday 04:00 | Read and write | ||||
| Schedule Tuesday 05:00 | Read and write | ||||
| Schedule Tuesday 06:00 | Read and write | ||||
| Schedule Tuesday 07:00 | Read and write | ||||
| Schedule Tuesday 08:00 | Read and write | ||||
| Schedule Tuesday 09:00 | Read and write | ||||
| Schedule Tuesday 10:00 | Read and write | ||||
| Schedule Tuesday 11:00 | Read and write | ||||
| Schedule Tuesday 12:00 | Read and write | ||||
| Schedule Tuesday 13:00 | Read and write | ||||
| Schedule Tuesday 14:00 | Read and write | ||||
| Schedule Tuesday 15:00 | Read and write | ||||
| Schedule Tuesday 16:00 | Read and write | ||||
| Schedule Tuesday 17:00 | Read and write | ||||
| Schedule Tuesday 18:00 | Read and write | ||||
| Schedule Tuesday 19:00 | Read and write | ||||
| Schedule Tuesday 20:00 | Read and write | ||||
| Schedule Tuesday 21:00 | Read and write | ||||
| Schedule Tuesday 22:00 | Read and write | ||||
| Schedule Tuesday 23:00 | Read and write | ||||
| Schedule Wednesday 00:00 | Read and write | ||||
| Schedule Wednesday 01:00 | Read and write | ||||
| Schedule Wednesday 02:00 | Read and write | ||||
| Schedule Wednesday 03:00 | Read and write | ||||
| Schedule Wednesday 04:00 | Read and write | ||||
| Schedule Wednesday 05:00 | Read and write | ||||
| Schedule Wednesday 06:00 | Read and write | ||||
| Schedule Wednesday 07:00 | Read and write | ||||
| Schedule Wednesday 08:00 | Read and write | ||||
| Schedule Wednesday 09:00 | Read and write | ||||
| Schedule Wednesday 10:00 | Read and write | ||||
| Schedule Wednesday 11:00 | Read and write | ||||
| Schedule Wednesday 12:00 | Read and write | ||||
| Schedule Wednesday 13:00 | Read and write | ||||
| Schedule Wednesday 14:00 | Read and write | ||||
| Schedule Wednesday 15:00 | Read and write | ||||
| Schedule Wednesday 16:00 | Read and write | ||||
| Schedule Wednesday 17:00 | Read and write | ||||
| Schedule Wednesday 18:00 | Read and write | ||||
| Schedule Wednesday 19:00 | Read and write | ||||
| Schedule Wednesday 20:00 | Read and write | ||||
| Schedule Wednesday 21:00 | Read and write | ||||
| Schedule Wednesday 22:00 | Read and write | ||||
| Schedule Wednesday 23:00 | Read and write | ||||
| Schedule Thursday 00:00 | Read and write | ||||
| Schedule Thursday 01:00 | Read and write | ||||
| Schedule Thursday 02:00 | Read and write | ||||
| Schedule Thursday 03:00 | Read and write | ||||
| Schedule Thursday 04:00 | Read and write | ||||
| Schedule Thursday 05:00 | Read and write | ||||
| Schedule Thursday 06:00 | Read and write | ||||
| Schedule Thursday 07:00 | Read and write | ||||
| Schedule Thursday 08:00 | Read and write | ||||
| Schedule Thursday 09:00 | Read and write | ||||
| Schedule Thursday 10:00 | Read and write | ||||
| Schedule Thursday 11:00 | Read and write | ||||
| Schedule Thursday 12:00 | Read and write | ||||
| Schedule Thursday 13:00 | Read and write | ||||
| Schedule Thursday 14:00 | Read and write | ||||
| Schedule Thursday 15:00 | Read and write | ||||
| Schedule Thursday 16:00 | Read and write | ||||
| Schedule Thursday 17:00 | Read and write | ||||
| Schedule Thursday 18:00 | Read and write | ||||
| Schedule Thursday 19:00 | Read and write | ||||
| Schedule Thursday 20:00 | Read and write | ||||
| Schedule Thursday 21:00 | Read and write | ||||
| Schedule Thursday 22:00 | Read and write | ||||
| Schedule Thursday 23:00 | Read and write | ||||
| Schedule Friday 00:00 | Read and write | ||||
| Schedule Friday 01:00 | Read and write | ||||
| Schedule Friday 02:00 | Read and write | ||||
| Schedule Friday 03:00 | Read and write | ||||
| Schedule Friday 04:00 | Read and write | ||||
| Schedule Friday 05:00 | Read and write | ||||
| Schedule Friday 06:00 | Read and write | ||||
| Schedule Friday 07:00 | Read and write | ||||
| Schedule Friday 08:00 | Read and write | ||||
| Schedule Friday 09:00 | Read and write | ||||
| Schedule Friday 10:00 | Read and write | ||||
| Schedule Friday 11:00 | Read and write | ||||
| Schedule Friday 12:00 | Read and write | ||||
| Schedule Friday 13:00 | Read and write | ||||
| Schedule Friday 14:00 | Read and write | ||||
| Schedule Friday 15:00 | Read and write | ||||
| Schedule Friday 16:00 | Read and write | ||||
| Schedule Friday 17:00 | Read and write | ||||
| Schedule Friday 18:00 | Read and write | ||||
| Schedule Friday 19:00 | Read and write | ||||
| Schedule Friday 20:00 | Read and write | ||||
| Schedule Friday 21:00 | Read and write | ||||
| Schedule Friday 22:00 | Read and write | ||||
| Schedule Friday 23:00 | Read and write | ||||
| Schedule Saturday 00:00 | Read and write | ||||
| Schedule Saturday 01:00 | Read and write | ||||
| Schedule Saturday 02:00 | Read and write | ||||
| Schedule Saturday 03:00 | Read and write | ||||
| Schedule Saturday 04:00 | Read and write | ||||
| Schedule Saturday 05:00 | Read and write | ||||
| Schedule Saturday 06:00 | Read and write | ||||
| Schedule Saturday 07:00 | Read and write | ||||
| Schedule Saturday 08:00 | Read and write | ||||
| Schedule Saturday 09:00 | Read and write | ||||
| Schedule Saturday 10:00 | Read and write | ||||
| Schedule Saturday 11:00 | Read and write | ||||
| Schedule Saturday 12:00 | Read and write | ||||
| Schedule Saturday 13:00 | Read and write | ||||
| Schedule Saturday 14:00 | Read and write | ||||
| Schedule Saturday 15:00 | Read and write | ||||
| Schedule Saturday 16:00 | Read and write | ||||
| Schedule Saturday 17:00 | Read and write | ||||
| Schedule Saturday 18:00 | Read and write | ||||
| Schedule Saturday 19:00 | Read and write | ||||
| Schedule Saturday 20:00 | Read and write | ||||
| Schedule Saturday 21:00 | Read and write | ||||
| Schedule Saturday 22:00 | Read and write | ||||
| Schedule Saturday 23:00 | Read and write | ||||
| Schedule Sunday 00:00 | Read and write | ||||
| Schedule Sunday 01:00 | Read and write | ||||
| Schedule Sunday 02:00 | Read and write | ||||
| Schedule Sunday 03:00 | Read and write | ||||
| Schedule Sunday 04:00 | Read and write | ||||
| Schedule Sunday 05:00 | Read and write | ||||
| Schedule Sunday 06:00 | Read and write | ||||
| Schedule Sunday 07:00 | Read and write | ||||
| Schedule Sunday 08:00 | Read and write | ||||
| Schedule Sunday 09:00 | Read and write | ||||
| Schedule Sunday 10:00 | Read and write | ||||
| Schedule Sunday 11:00 | Read and write | ||||
| Schedule Sunday 12:00 | Read and write | ||||
| Schedule Sunday 13:00 | Read and write | ||||
| Schedule Sunday 14:00 | Read and write | ||||
| Schedule Sunday 15:00 | Read and write | ||||
| Schedule Sunday 16:00 | Read and write | ||||
| Schedule Sunday 17:00 | Read and write | ||||
| Schedule Sunday 18:00 | Read and write | ||||
| Schedule Sunday 19:00 | Read and write | ||||
| Schedule Sunday 20:00 | Read and write | ||||
| Schedule Sunday 21:00 | Read and write | ||||
| Schedule Sunday 22:00 | Read and write | ||||
| Schedule Sunday 23:00 | Read and write | ||||
| CFi Supply Airflow | Read | ||||
| CFi Extract Airflow | Read | ||||
| CFi Maximum Airflow | Read and write | ||||
| CFi Minimum Airflow | Read and write |
Loading registers…
Send your device list
If a device is not in the library yet, we build the template for free as soon as we have the register data.
Use cases
- Show fan speed, supply and outdoor air temperature, humidity and CO2 of a Vallox unit on one ModbusCloud dashboard.
- Get an email when Critical Fault Active switches on or Filter Remaining Days drops below a threshold you set.
- Track the air temperatures around the heat exchanger in the 365-day history to see how well heat is recovered.
- Switch a unit to away mode remotely from the portal when a building is empty.
- Read the fault codes of the last ten faults before you drive to a site.
- Change the home mode fan speed or supply temperature setting remotely.
Installation
On the MyVallox panel open Expert settings, I/O and bus settings, Modbus settings and set address, baud rate, parity and stop bits.
Connect RS485 A and B of the unit to the RS485 port of the ModbusCloud Gateway, with a 120 ohm termination at both ends of the bus.
In ModbusCloud, add a Modbus device with the same address, speed and parity, and import this template.
Check that Fan Speed and Outdoor Air Temperature show plausible values; subtract 273.15 from the kelvin value for degrees Celsius.
Things to watch for
The unit does not answer. What should I check?
Compare address, baud rate, parity and stop bits with the Modbus settings in MyVallox. Swap A and B and add a 120 ohm termination at both ends of the bus. Vallox units only support Modbus RTU, not Modbus TCP.
Why do temperatures show around 290?
The unit sends temperatures in centikelvin. The template shows them in kelvin, so 293.15 means 20 °C. Subtract 273.15 for degrees Celsius.
Why does a write return an error?
The unit rejects writes to read-only or undefined registers and values outside the allowed range. Writing registers is off per Gateway until it is enabled on request; write only values you understand, such as 0 or 1 to Ventilation Profile or minutes to Boost Timer.
Fan speed settings show large numbers instead of percent. Why?
On MyVallox CFi units the fan speed setting registers hold airflow in l/s or m³/h instead of percent, between the minimum and maximum airflow of the unit. Fan Speed itself is only available on units with percent control.
Can several units share one bus?
Yes, up to 32 units on one RS485 bus. Give each unit its own Modbus address in MyVallox and add each one as a separate Modbus device in ModbusCloud with this template.
Want to see how it works?
