Haier Water Heater

The haier_water_heater water heater platform controls a Haier water heater over UART, replacing its original Wi-Fi module. It uses hOn automatically and supports power, operating mode, target temperature, and status monitoring. SmartAir2 is not supported.

Hardware testing has only been performed with a VH3W. Compatibility with other models is unverified. For air conditioners, use Haier Climate.

Connection

Configure a UART bus with RX and TX, a baud rate of 9600, eight data bits, no parity, and one stop bit. Disconnect the original Wi-Fi module before connecting the ESP controller. Connect the heater’s TX to the controller’s RX, the heater’s RX to the controller’s TX, and a common ground. Verify the connector pinout and signal voltage for your appliance; the climate-device pinout is not a water-heater wiring reference.

VH3W Connector

The tested VH3W has a 4-pin JST XH connector located at the heater’s display. The original cable uses wires in the order Red, Black, Yellow, White. The table identifies connections by the original cable’s wire colours.

Wire Colour	Heater Connection	ESP Controller Connection
Red	5 V supply	Board power input rated for 5 V
Black	Ground	GND
Yellow	Heater TX	UART RX
White	Heater RX	UART TX

The TX and RX names above are relative to the heater. Configure the GPIO connected to the yellow wire as rx_pin and the GPIO connected to the white wire as tx_pin in the UART configuration. Connect the red wire only to a board power input rated for 5 V, not to a GPIO or the 3.3 V pin. The 5 V supply does not establish the UART signal voltage; verify signal-level compatibility with your board.

Configuration

water_heater:
  - platform: haier_water_heater
    name: "Water Heater"

Configuration Variables

• uart_id (Optional, ID): The UART bus to use. Required if multiple UART buses are configured.
• communication_timeout (Optional, Time): Time without a valid heater status before communication is reported as disconnected. Defaults to 20s. Shorter values may cause false disconnects during periodic device-information requests. This setting also controls the component warning when no communication sensor is configured.
• All other options from Water Heater. The platform has no supported_modes option: its modes are fixed to Off, Electric, Eco and Performance.

Optional Sensors

Each sensor is created only when configured. Temperature and available-water sensors support all options from Sensor. The estimated heating-time sensor also supports those options.

• primary_temperature (Optional): The current temperature shown on the heater’s display, in degrees Celsius. This is also the main water-heater entity’s current temperature.
• secondary_temperature (Optional): A second reported temperature, in degrees Celsius. Its physical sensor location is not confirmed.
• target_temperature (Optional): A read-only copy of the reported target temperature, in degrees Celsius. Use the main water-heater entity to change the target.
• estimated_heating_time (Optional): The heater’s estimated remaining heating time. The unit is assumed to be minutes and has not been independently confirmed. The value may remain nonzero while the heater is off.
• available_water (Optional): Estimated usable hot water as 0%, 33%, 66%, or 100%. This is not the tank fill level. Unexpected raw values publish an unknown sensor value.

The following support all options from Binary Sensor:

• communication (Optional): A diagnostic connectivity sensor. Starts disconnected, becomes connected after a valid heater status, and becomes disconnected after communication_timeout without another valid status.
• power (Optional): Whether the heater is powered on rather than in standby.
• heating (Optional): Whether the heater reports heating activity.

The mode (Optional) Text Sensor reports Normal, ECO, BPS, or Unknown.

Operating Modes And Temperature Control

ESPHome mode	Heater mode
Off	Standby
Electric	Normal
Eco	ECO
Performance	BPS

Selecting an active mode also powers on an off heater. Power-on alone preserves the heater’s selected mode. Manual target temperatures are whole degrees from 35 to 75 degrees Celsius in Normal mode. Select Electric and wait for the reported mode to change before adjusting the target in ECO or BPS. BPS reports its own target; the tested VH3W reports 80 degrees Celsius. ECO manages its target automatically.

In Home Assistant, use the main water-heater entity’s controls to change temperature and mode. The optional target-temperature sensor only displays the reported target.

Commands require a status received within the last 15 seconds. Off is an exception: it cancels unsent commands, ignores an accompanying target temperature, and waits for the current exchange to finish or time out before being sent. Other requests are rejected while a command sequence is in progress. Controls are confirmed from received status rather than published optimistically. Failed commands are not automatically retried.

If an unknown mode is received, a warning is logged and the mode text sensor reports Unknown. While the heater is on, the main entity retains the last recognized active mode, or uses Electric as a display fallback if none is known. This does not send a mode command or allow temperature writes in an unknown mode.

Communication And Network Indication

The controller polls the heater every five seconds when no other exchange takes priority, and periodically requests device information. Communication loss and recovery are logged. Sensor readings retain their last values during communication loss; use the communication sensor to determine whether status is current. An acknowledgement alone does not establish communication health.

The controller automatically updates the heater’s network indicator. Wi-Fi or Ethernet connected with an IP address reports network-ready; no network connection reports not-ready. This indicates local network readiness, not internet access, a cloud connection, or a connection to Home Assistant. There is no manual network selector.

Example With Optional Sensors

water_heater:
  - platform: haier_water_heater
    name: "Water Heater"
    communication_timeout: 20s
    primary_temperature:
      name: "Primary temperature zone"
    secondary_temperature:
      name: "Secondary temperature zone"
    target_temperature:
      name: "Heater Target Temperature"
    estimated_heating_time:
      name: "Heater Estimated Heating Time"
    available_water:
      name: "Heater Available Water"
    communication:
      name: "Heater Communication"
    power:
      name: "Heater Power"
    heating:
      name: "Heater Heating"
    mode:
      name: "Heater Mode"

See Also

• Water Heater
• UART Bus
• Haier Climate