Petkit W5 Water Fountain

BLE Device

The W5 water fountain communicates via Bluetooth Low Energy (BLE) through a nearby Petkit device acting as a BLE proxy (see Bluetooth Devices Overview). The proxy must be present on the network and within Bluetooth range of the fountain. Localkit receives status updates from the fountain and can also send commands to it (power, mode, filter reset).

The Petkit W5 is a smart pet water fountain. Localkit decodes BLE advertisements from the device and exposes its status as Home Assistant entities via MQTT. Supported variants include W5, W5C, W4X, and CTW3.

Acknowledgement

The BLE protocol implementation is based on the work of slespersen/PetkitW5BLEMQTT. Many thanks for reverse engineering the W5 BLE protocol.

Controls (Writable)

These appear as Switch, Select, and Button entities in Home Assistant under the config category. Saving sends the command to the fountain over BLE via the linked proxy.

Name	Type	Technical Name	Description
Power	Switch	power_status	Turns the fountain on or off
Mode	Select	mode	Fountain mode: Normal or Smart
Reset Filter	Button	action_reset_filter	Resets the filter counter after replacing the filter
Refresh Device Data	Button	action_refresh_data	Makes the proxy reconnect over BLE and pull a fresh status

Power and mode can also be changed from the device detail form in the Localkit Web UI. The Refresh Device Data and Reset Filter actions are available as row actions in the Bluetooth Devices list.

Binary Sensors (Read-only)

These appear as Binary Sensor entities in Home Assistant under the diagnostic category.

Name	Technical Name	Device Class	Description
Running	running_status	power	on when the pump is actively running
Do Not Disturb Active	dnd_state	—	on while the DND schedule is active
Do Not Disturb	do_not_disturb_switch	—	on when the DND schedule is enabled
LED Switch	led_switch	—	on when the LED is enabled
Warning: Breakdown	warning_breakdown	problem	on when a hardware fault is detected
Warning: Water Missing	warning_water_missing	problem	on when the water level is too low
Warning: Filter	warning_filter	problem	on when the filter needs attention

Sensors (Read-only)

These appear as Sensor entities in Home Assistant under the diagnostic category.

Name	Technical Name	Unit	Description
Filter %	filter_percentage	%	Remaining filter capacity (0–100)
Filter Time Left	filter_time_left	d	Estimated days until filter replacement
Last Update	last_update	—	Timestamp of the last accepted status frame
Do Not Disturb Time On	do_not_disturb_time_on	—	Start of the quiet period (HH:MM)
Do Not Disturb Time Off	do_not_disturb_time_off	—	End of the quiet period (HH:MM)
Smart Mode Time On	smart_time_on	min	Smart mode on-duration
Smart Mode Time Off	smart_time_off	min	Smart mode off-duration
LED Brightness	led_brightness	—	LED brightness level
LED Light Time On	led_light_time_on	—	LED on-time (HH:MM)
LED Light Time Off	led_light_time_off	—	LED off-time (HH:MM)
Pump Runtime	pump_runtime	—	Total pump runtime (lifetime)
Pump Runtime Today	pump_runtime_today	—	Pump runtime today
Purified Water	purified_water	L	Total liters of water purified (lifetime)
Purified Water Today	purified_water_today	L	Liters purified today
Energy Consumption	energy_consumed	kWh	Total energy used
Link With	link_with	—	Name of the Petkit proxy device this fountain is linked to

Data Quality

The fountain occasionally sends malformed or truncated status frames. Localkit rejects these instead of parsing them into zeroed values — the last known good state is kept, and the Last Update sensor always shows when the last valid frame was received. If the sensor grows stale, check that the linked proxy is online and within Bluetooth range, then use the Refresh Device Data button.

Supported Device Variants

Alias	Flow Rate	Pump Divisor	Power Draw
W5	1.5 L/min	2.0	0.75 W
W5C	1.3 L/min	1.0	0.182 W
W4X	1.5 L/min	1.8	0.75 W
CTW3	1.5 L/min	3.0	0.75 W

The variant affects how pump runtime is translated into purified water volume and energy consumption figures.