Lambda Heating & Cooling

Use cases

• Monitor buffer and hot water storage temperatures on a live cloud dashboard for your customer.
• Create an alert when the COP drops below a defined threshold to detect efficiency problems early.
• Adjust hot water target temperature remotely to align heat pump operation with PV surplus or flexible tariffs.
• Track power consumption and thermal output over time to generate monthly performance reports.
• Switch heating circuit operating modes based on seasonal schedules or occupancy patterns.
• Integrate E-Manager input power control to coordinate the heat pump with on-site energy management.

Installation

1. 1Activate Modbus TCP or RTU on the Lambda heat pump following the instructions in the Lambda Helpcenter download area.
2. 2Connect the ModbusCloud gateway (MCG or MLP series) to the heat pump via Ethernet for Modbus TCP, or via RS-485 wiring (A, B, GND) for Modbus RTU.
3. 3Set the correct Modbus slave address on the heat pump to match the address configured in the template.
4. 4For Modbus RTU connections, verify that the baud rate, parity, and stop bits on the gateway match the heat pump settings.
5. 5Import the Lambda Heating & Cooling template in the ModbusCloud portal and assign it to the connected gateway.
6. 6Verify that live readings such as buffer temperatures and power consumption appear on the ModbusCloud dashboard.

Things to watch for

01

I cannot read any registers after connecting via Modbus TCP. What should I check?

Modbus TCP must be explicitly activated on the Lambda heat pump. Check the Lambda Helpcenter for the activation procedure. Also verify that the gateway and heat pump are on the same network subnet and that the correct IP address is configured in ModbusCloud.

02

What data types and scaling do the temperature registers use?

Most temperature and power registers use int16 with values in degrees Celsius or kW. Flow line temperature offset registers 5050 and 5150 are uint16. The template already includes the correct data type and scaling, so no manual adjustments are required.

03

Which Lambda models are supported by this template?

The template supports EU08L, EU13L, EU15L, and EU20L. Zewotherm branded versions of the same models (Zewotherm EU08L through EU20L) are also compatible, as the Modbus register map is identical.

04

Can I use Modbus RTU and Modbus TCP at the same time?

Refer to the Lambda documentation for details on simultaneous protocol support. In most cases, the heat pump supports one active Modbus connection at a time. Choose the protocol that matches your ModbusCloud gateway hardware.

Registers (32)

27 read / 8 write

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