NORDline WWBA
Controls NORDline air-to-water heat pumps via Modbus RTU
NORDline WWBA is a series of air-to-water heat pumps controllable via Modbus RTU at 9600 baud. This template reads temperature sensors, compressor status, and error codes while providing full mode and setpoint control. Compatible models include WWBA9.5 H-B/P, WWBA13.5 H-B-S, and WWBA19.5 H-B-S.
- Protocol
- Modbus RTU
- Connection
- RS485, 9600 baud
- Registers
- 17, read and write
- Brand
- NORDline
- Key readings
- Output temperature · DHW tank temperature · UFA tank temperature · Evaporator coil temperature · Discharge gas temperature · Error codes 1 to 5
- Available commands
- Mode (cooling, heating, FCU) · Water pump mode · FCU heating temp set point · Floor heating outlet temperature
- Compatible models
- WWBA9.5 H-B/P · WWBA13.5 H-B-S · WWBA19.5 H-B-S
- Last updated
Registers (17)
16 read, 4 write
| Name | Unit | Access | Address (Hidden until you enter your email) | Function (hidden) | Type (hidden) |
|---|---|---|---|---|---|
| Mode | Read and write | ||||
| Output temperature | °C | Read | |||
| Control mark | Read | ||||
| Status output 1 | Read | ||||
| control mark 2 | Read | ||||
| Error 1 | Read | ||||
| Error 4 | Read | ||||
| Error 5 | Read | ||||
| Error 2 | Read | ||||
| DHW tank temperature | °C | Read | |||
| UFA tank temperature_ | °C | Read | |||
| Water pump mode | Read and write | ||||
| Evaporator coil temperature | °C | Read | |||
| Reverse temperature | °C | Read | |||
| Temperature of discharge gas | °C | Read | |||
| FCU heating temp set point | °C | Read and write | |||
| Outlet temperature of floor heating | °C | Write |
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Use cases
- Monitor outlet water and DHW tank temperatures on a live cloud dashboard for remote customer support.
- Switch between cooling, heating, and FCU heating modes remotely without a site visit.
- Create an alert when any of the five error codes becomes active to reduce response time.
- Adjust floor heating outlet temperature setpoints based on outdoor conditions or customer requests.
- Track compressor run status and discharge gas temperature to schedule preventive maintenance.
- Log evaporator coil temperature over time to detect early signs of refrigerant issues.
Installation
Wire the ModbusCloud Gateway to the NORDline WWBA RS-485 terminals, observing correct A and B polarity.
Terminate the RS-485 bus with a 120 ohm resistor at both ends if the gateway is the last device on the bus.
On the NORDline WWBA controller, set a unique Modbus slave address and confirm the baud rate is 9600, 8N1.
In the ModbusCloud portal, import the NORDline WWBA template and enter the matching slave address.
Verify communication by checking that output temperature and compressor status values appear on the dashboard.
Configure alerts or automations for error codes and temperature thresholds as needed.
Things to watch for
The gateway cannot communicate with the heat pump. What should I check first?
Verify that the RS-485 A and B wires are not swapped. Also confirm the baud rate on the heat pump is set to 9600 with 8 data bits, no parity, and 1 stop bit (8N1). Check that the slave address in ModbusCloud matches the address configured on the unit.
Can I use one template for different WWBA models?
Yes. The WWBA9.5 H-B/P, WWBA13.5 H-B-S, and WWBA19.5 H-B-S share the same Modbus register map. A single template instance works for any of these models.
Do I need a bus termination resistor?
If the ModbusCloud gateway is at one end of the RS-485 bus, place a 120 ohm termination resistor across the A and B lines. The heat pump end should also be terminated if it is the other physical end of the bus.
Temperature values look incorrect or scaled wrong. How do I fix this?
The template already includes the correct scaling factors for all temperature registers. If values still appear wrong, confirm you have imported the latest version of the NORDline WWBA template from the ModbusCloud library.
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