EmsTechLabs Logo EmsTechLabs

Esp32 Phnix Heroplus Heat Pump Modbus Register 2045: Inlet water Temperature

Technical documentation for Modbus register 2045 on Esp32 Phnix Heroplus Heat Pump. Data type: S WORD. Includes Python and YAML configuration examples.

January 16, 2026 3 read

Technical Definition

The register Inlet water Temperature at address 2045 is used to monitor inlet water Temperature on the Esp32 Phnix Heroplus Heat Pump.

  • Protocol: Modbus RTU
  • Data Type: S WORD
  • Unit: °C
  • Access: Read Only

How to Read (Python pymodbus)

Use this code snippet to read this specific value via RS485:

from pymodbus.client.sync import ModbusSerialClient

client = ModbusSerialClient(method='rtu', port='/dev/ttyUSB0', baudrate=9600)
client.connect()

# Read Inlet water temperature (Address: 2045)
# Note: Check if your device uses 0-based or 1-based addressing
result = client.read_input_registers(address=2045, count=2, unit=1)

if not result.isError():
    print(f"Raw Value: {result.registers}")
else:
    print("Error reading register")

client.close()

Integration (Home Assistant)

Paste this into your configuration.yaml:

- platform: modbus_controller
  name: "Inlet water temperature"
  address: 2045
  value_type: S_WORD
  unit_of_measurement: "°C"

Connection Diagram

Here is the standard RS485 wiring for this configuration:

graph TD
    PLC[Host Controller / Home Assistant]
    Device[Esp32 Phnix Heroplus Heat Pump]

    PLC -- "A+ (D+)" --> Device
    PLC -- "B- (D-)" --> Device
    PLC -- GND --> Device


💡 Engineer's Insight

Analysis: Temperature of the water entering the heat pump system. Units: Degrees Celsius (°C) or Fahrenheit (°F).

Troubleshooting: Low/zero readings could point to pump failure, frozen pipes, or sensor malfunction.