--- title: "Atrea RD5 Air Recovery" description: "Atrea DUPLEX heat recovery ventilation units with RD5 controller connected to TapHome via Modbus TCP." url: "https://taphome.com/en/compatibility/atrea-rd5-air-recovery/" language: en lastmod: 2026-03-15 generator: hugo ai: topics: ["modbus-tcp","air-recovery","ventilation","hvac","temperature-monitoring"] questions: ["How to integrate Atrea DUPLEX ventilation with TapHome?","What does the Atrea RD5 TapHome template measure and control?","How to connect Atrea RD5 via Modbus TCP to TapHome?","How to change ventilation mode on Atrea DUPLEX from TapHome?","How to set temperature setpoint on Atrea RD5 through TapHome?","How to troubleshoot Modbus TCP connection to Atrea RD5?"] --- # Atrea RD5 Air Recovery Communication: Modbus TCP - [Atrea Official Website](https://www.atrea.eu/en/) - [Atrea Documents](https://atrea.eu/en/documents/) Atrea DUPLEX series are mechanical ventilation heat recovery (MVHR) units controlled by the RD5 regulation system. TapHome connects directly to the RD5 controller via Modbus TCP over Ethernet — no additional gateway is required. The template provides thermostat control with temperature setpoint, operating mode selection (Off, Auto, Ventilation, Circulation, Night Precooling, Balance, Overpressure), fan power adjustment (0–100%), four temperature sensors (supply, indoor, outdoor, extract), and comprehensive diagnostics with 45+ error and warning registers. ## Network connection The RD5 controller has a built-in Ethernet interface. Connect it to the same local network as TapHome Core using a standard Ethernet cable. - **Protocol:** Modbus TCP - **Port:** 502 - **Slave ID:** 1–255 (configurable) - **Data encoding:** Int16, temperature values divided by 10 ## Enabling Modbus TCP Modbus TCP must be explicitly enabled in the RD5 service settings before TapHome can communicate with the unit. Navigate to service parameter **3.15.1 Modbus TCP** and set it to **YES**. > [!WARNING] > If Modbus TCP is not enabled (parameter 3.15.1 = NO), the RD5 controller will not respond to any Modbus TCP requests on port 502. ## Configuration When importing the template in TapHome, provide: - **IP Address** — the RD5 controller's IP on the local network - **Slave ID** — Modbus appliance address (default: 1) > [!TIP] > Assign a static IP address to the RD5 controller in the router's DHCP settings to prevent the address from changing after a power cycle. > [!NOTE] > The manufacturer recommends using the **Manual** control routine when the unit is controlled from a BMS system such as TapHome. The template writes control registers (H:10708, H:10709, H:10710) that correspond to the Manual routine (H:10700–H:10703 = 0). ## Device capabilities The template exposes the following devices: ### Thermostat - **Atrea Thermostat** — room temperature control with setpoint range 10–40 °C. Reads current temperature from I:10212 (T-SUP), reads desired temperature from H:10716, and writes the setpoint to H:10710. Includes 13 service attributes showing heating/cooling status (water valve, pump, heat pump, preheating, cooling configuration) and 6 service actions for configuring primary/secondary heating, preheating, cooling, capillary freezing protection, and room control sensor selection. ### Operating mode control - **Mode Control** — multi-value switch for selecting the operating mode via registers H:10705 (read) / H:10709 (write). Available modes: Off, Auto, Ventilation, Circulation + Ventilation, Circulation, Night Precooling, Balance, Overpressure. ### Fan control - **Ventilation** — dimmer controlling fan power from 0% (off) to 100% via registers H:10704 (read) / H:10708 (write). The minimum active power is 12%. Includes 4 service attributes (M1 output %, M2 output %, regulation mode, ventilation interval) and 2 service actions (fan regulation mode selection, ventilation interval setting 0–60 min). ### Temperature monitoring The template includes four temperature sensors: | Sensor | Register | Description | |--------|----------|-------------| | **T-SUP** (Supply) | I:10212 | Supply air temperature — air delivered to rooms after heat recovery | | **T-IDA** (Indoor) | I:10215 | Indoor air temperature — source selectable between CP Touch, T-ETA, TRKn, or BMS | | **T-ODA** (Outdoor) | I:10211 | Outdoor air temperature — built-in sensor or BMS-provided value | | **T-ETA** (Extract) | I:10213 | Extract air temperature — air extracted from rooms before heat recovery | > [!NOTE] > The T-IDA sensor source can be configured via the service action on the Indoor Air Temperature device. The T-ODA sensor can be switched between the built-in sensor and a BMS-provided value, with configurable sensor position (internal/external). ### Module-level diagnostics The RD5 template monitors 45+ discrete registers (D:11100–D:11184) for errors and warnings, including: - **Errors:** Device overheating, orientation not set, sensor failures (TU1/TU2/TEa/TEb/TA2/T-ODA/T-ETA), STP contact, manometer failures, RD-IO communication, unbalanced flow, configuration missing, insufficient preheating, module failures, frost protection - **Warnings:** Heat exchanger freezing/defrosting, high tariff, insufficient flow/heating, clogged filter, input alarm faults, uncommissioned unit, safe mode, cooling/heating unavailable A module-level service attribute shows the **Unit Orientation** (which motor is the supply fan), and a service action allows configuring the supply fan assignment (M1 or M2). ### Additional capabilities The RD5 units also expose Modbus registers for exhaust air temperature (T-EHA), forced mode status, season control, volume flow monitoring (supply/extract), filter replacement period, alarm/filter reset, and control routine configuration. These can be added to the TapHome template in a future update. ## Troubleshooting ### No Modbus communication 1. Verify that Modbus TCP is enabled — parameter **3.15.1 Modbus TCP = YES** in the service settings 2. Confirm the RD5 controller's IP address — check the router's DHCP lease table 3. Ensure TapHome Core and the RD5 controller are on the same network/subnet 4. Check that no firewall is blocking port 502 5. Respect the 5-second gap between multiple read/write operations as recommended by the manufacturer ### Temperature values appear incorrect Temperature registers use Int16 encoding with the value divided by 10. Values above 32767 represent negative temperatures: (value - 65536) / 10. For example, value 65516 = (65516 - 65536) / 10 = -2.0 °C. ### Mode changes not applied When the unit is in a forced mode (startup, run-down, defrost, D1–D4 input activation), mode write commands may be ignored. Check the forced mode register H:10712 — value 0 means no forced mode is active. If using the Schedule control routine (H:10700–H:10703 = 1), you must first write value 2 to the corresponding control routine register before writing the new control parameter. ## Available devices Atrea RD5 Module Service Attributes | | |------------------| | Unit Orientation | Service Actions | | |------------------------| | Set Supply Orientation | Atrea Thermostat Thermostat Room temperature control — setpoint, current and desired temperature Register: I:10212 (read current), H:10716 (read desired), H:10710 (write desired) Int16 Unit: °C numeric (value / 10 = °C) Service Attributes | | |---------------------------------| | Heating Water Valve YV1 | | Heating Water Pump KK | | Heating (Water or Electric) SA2 | | Heat Pump (Heating) DA1 | | Heat Pump (Heating) SE | | Heat Pump (Cooling) DA1 | | Heat Pump (Cooling) SC | | Temp. sensor for Room Control | | Preheating | | Cooling | | Capillary freezing | | Primary Heating | | Secondary heating | Service Actions | | |-------------------------------| | Temp. sensor for Room Control | | Primary Heating | | Secondary heating | | Preheating | | Cooling | | Capillary Freezing | Supply Air Temperature (T-SUP) Temperature Sensor Read-only Register: I:10212 Int16 Unit: °C numeric (value / 10 = °C) Indoor Air Temperature (T-IDA) Temperature Sensor Read-only Indoor air temperature — source selectable between CP Touch panel, T-ETA, TRKn, or BMS Register: I:10215 Int16 Unit: °C numeric (value / 10 = °C) Service Attributes | | |--------| | Source | Service Actions | | |-----------------| | Source of T-IDA | Mode Control Multi-value Switch Active operating mode — Off, Auto, Ventilation, Circulation, Night Precooling, Balance, or Overpressure Register: H:10705 (read), H:10709 (write) Int16 numeric Values / States: OFF · Auto · Ventilation · Circulation + Ventilation · Circulation · Night Precooling · Balance · Overpressure Outdoor Air Temperature (T-ODA) Temperature Sensor Read-only Outdoor air temperature — from built-in sensor or BMS-provided value Register: I:10211 Int16 Unit: °C numeric (value / 10 = °C, negative: (value − 65536) / 10) Service Attributes | | |------------------| | Source for T-ODA | | Sensor Position | Service Actions | | |-----------------------| | Choose Source | | T-ODA Sensor Position | Extract Air Temperature (T-ETA) Temperature Sensor Read-only Register: I:10213 Int16 Unit: °C numeric (value / 10 = °C) Ventilation Dimmer Fan power control — adjusts ventilation intensity with M1/M2 motor monitoring Register: H:10704 (read power), H:10708 (write power) Int16 Unit: % numeric (0=Off, 12–100 = power %) Service Attributes | | |-----------------------------| | M1 | | M2 | | Regulation M1 / M2 | | Ventilation Interval (Auto) | Service Actions | | |-----------------------------| | Regulation M1/M2 | | Ventilation Interval (Auto) | **Connection:** Modbus TCP • Slave ID: $\[SlaveId] Possible improvements (19) - I:10214 Exhaust Air Temperature (T-EHA) — Int16, value / 10 = °C, read-only — air temperature after heat recovery (exhaust side) - H:10706 Required Temperature (read) — Int16, value / 10 = °C — currently set temperature target, read-only - H:10704 Required Power (read) — Int16, 0–100% — currently set fan power, read-only - H:10712 Forced Mode Status — Int16, 0–32 — shows if unit is in a forced mode (startup, rundown, defrost, D1–D4, etc.) - I:11401 Current Season — 0=Heating Season, 1=Non-Heating Season - H:11401 Season Control — R/W, 0=HS, 1=NHS, 2=T-ODA, 3=T-ODA+ — manual or automatic season switching - I:11600 Required Supply Volume Flow — 0–15000 m3/h - I:11601 Current Supply Volume Flow — 0–15000 m3/h - I:11602 Required Extract Volume Flow — 0–15000 m3/h - I:11603 Current Extract Volume Flow — 0–15000 m3/h - H:10910 Filter Replacement Period — R/W, 0–365 days - C:10005 Alarm Reset — Write 1 to reset all resetable alarms - C:10007 Filter Reset — Write 1 to reset filter change interval counter - H:10700 Power Control Routine — R/W, 0=Manual, 1=Schedule, 2=Temporary — BMS should use Manual (0) - H:10701 Mode Control Routine — R/W, 0=Manual, 1=Schedule, 2=Temporary - H:10702 Temperature Control Routine — R/W, 0=Manual, 1=Schedule, 2=Temporary - H:10703 Zone Control Routine — R/W, 0=Manual, 1=Schedule, 2=Temporary - H:10707 Required Zone — R/W, 0=Both, 1=Zone 1, 2=Zone 2 — requires SZ1/SZ2 function enabled - I:11420 Average Outdoor Temperature — Int16, averaged T-ODA over configurable time window ## Sources - Index Table for Modbus TCP — RD5 Control System [atrea.eu](https://atrea.eu/en/documents/) 2026-03-15 [PDF](https://taphome.com/compatibility/devices/atrea-rd5-air-recovery/manufacturer/RD5_parameters_EN.pdf) - pyatrea — Python Library for Atrea Ventilation Units [github.com](https://github.com/JurajNyiri/pyatrea) 2026-03-15 ## Related Documentation - [Modbus Integration](https://taphome.com/en/compatibility/modbus-guide/) - [Modbus](https://taphome.com/en/docs/integration/modbus/) - [Simple configuration using templates](https://taphome.com/en/docs/integration/modbus/templates/) - [Modbus scripts and prefetch](https://taphome.com/en/docs/script/modbus-scripts/) - [Modbus functions](https://taphome.com/en/docs/script/modbus/) - [Modbus data types](https://taphome.com/en/docs/script/modbus-data-types/)