This store requires javascript to be enabled for some features to work correctly.

Water Level Monitoring Sensor


Product Support



File Type


Quick Start Guide


Frequently-Asked Questions

What are the differences between the YoLink Water Leak Sensor 2, Water Leak Sensor 3, and Water Level Sensor?

The YoLink Water Leak Sensor 2, Water Leak Sensor 3, and Water Level Sensor are all YS7904 Water Leak Sensors, but they differ in the type of sensor cable or probe they use.

The Water Leak Sensor 2 uses a gray sensor cable that detects water along the length of the cable. The Water Leak Sensor 3 uses a white sensor probe cable that detects water only at the probe at the end of the cable.

The Water Level Sensor uses a float switch cable that has a reed switch and magnet. When the switch is submerged in water, the magnet and reed switch connect, indicating the presence of water at that level.

All three sensors can be set to detect the presence of water, but the Water Level Sensor is recommended for detecting when water levels have reached a certain point and need to be emptied.

It's important to note that the sensors are designed for different applications and use cases, so it's important to choose the appropriate sensor for your specific needs.

 In automation, what is the difference between "Water Detected" and "Water Leak Alert"?

"Water Detected" refers to the exact moment when the YoLink Water Leak Sensor detects the presence of water. This trigger can be used to activate automations or routines that respond to the initial detection of water.

"Water Leak Alert" refers to each subsequent alert sent by the sensor if you have set up an alert interval. For example, if you set the alert interval to 4 hours, you will receive a "Water Leak Alert" every 4 hours until the sensor no longer detects water. This trigger can also be used to activate automations or routines that respond to ongoing water detection.

In summary, "Water Detected" is the initial trigger for water detection, while "Water Leak Alert" refers to ongoing alerts sent by the sensor at a specified interval.

Can I receive a phone call if water is detected by the YoLink Water Leak Sensor?

Yes, you can receive a phone call if water is detected by connecting the YoLink Water Leak Sensor with IFTTT. You can create an "IF" statement that says "the Water Leak Sensor detects a leak warning", and then set the "THEN" statement to "Call you". This will trigger a phone call to be made to your specified phone number when the Water Leak Sensor detects water.

To set this up, you will need to have an IFTTT account and connect it with your YoLink account. Then, create a new applet that links the Water Leak Sensor to the "Call you" action. If you have any issues setting this up, you can refer to the IFTTT help center or contact YoLink customer support for further assistance.

Can the YoLink Water Leak Sensors be used in freezing temperatures?

Yes, the YoLink Water Leak Sensors 2 can be used in freezing temperatures. The recommended operating temperature range for the sensors is from -20°C to 50°C (-4°F to 122°F), which means that they can withstand a wide range of temperatures. However, it's important to note that the battery capacity of the sensor will be significantly reduced in low temperatures, and there may be a risk of battery explosion in high temperatures, which could have a negative impact on the device.

If you plan to use the Water Leak Sensor 2 in extreme temperature conditions, it is recommended to use lithium battery, which is better suited to handle temperature fluctuations.

The YoLink Water Leak Detector provides a temperature value on the detailed App page. What is the purpose of this feature?

The temperature value displayed on the YoLink Water Leak Detector's details page is used to detect the ambient temperature around the sensor. This feature is mainly designed to help users monitor the temperature in areas where the Water Leak Sensor is installed.

However, it's important to note that this temperature value cannot be used to detect the temperature of the entire room or trigger actions based on temperature changes. The feature is simply meant to provide additional information to the user about the ambient temperature in the immediate vicinity of the sensor.

It's also important to note that the temperature display is an auxiliary function and the temperature updates are not frequent or real-time due to chip limitations. The temperature will only update when the sensor sends an alert, heartbeat signal, or the SET button is pressed.

 I accidentally triggered the water alarm on my YoLink Water Leak Sensor 2 by lightly wetting the gray sensor cable. How can I turn off the water alarm?

If you accidentally trigger the water alarm on your YoLink Water Leak Sensor 2, you can clear the alert by drying the sensor cable thoroughly. You can try tapping the end of the probe to shake out any water, blowing into the probe to blow out any water, or using a hair dryer (with caution to avoid melting the cable).

Alternatively, you can hang the sensor cable so that the probe (phono socket) hangs downwards, allowing any water to fall out and the sensor to dry on its own.

It's recommended to have spare cables as backup. If water is detected, you can replace the sensor cable with a spare one.

How can I close the valve when the sensor detects water?

There are two ways to close the valve when the sensor detects water:

Create automation in the YoLink app (requires internet connection):

When: Water leak sensor detects a water leak (triggers an alert)

Then: Valve controller closes the valve

Set up YoLink Control, make sure the firmware of the valve controller is 090e or newer (no internet required) if you use YS4909 valve controller:

First, close the valve. Next, press and hold the set button on the water leak sensor until the green LED starts blinking rapidly. Then, press and hold the set button on the valve controller until its green LED also blinks rapidly. This establishes a direct connection between the devices without the need for an internet connection.

 Is there any way to configure a relay to shut something off if a condition is met? Ex, my pool pump is in a closed room, if it ever failed and leaked I’d like to shut it off automatically instead of being alerted and having to do it manually.

Yes, you can configure a relay to automatically shut off your pool pump if a certain condition is met, such as detecting a water leak. Considering that pool pumps have high starting currents, you should use a YoLink Relay in conjunction with a heavy-duty "dumb" relay to handle the pool pump's power requirements.

You can follow the instructions in the YoLink Relay manual to set up the relay system.

Additionally, you'll need a water leak sensor to detect any leaks. Once you have both the relay and sensor installed, you can create an automation rule: when the water leak sensor detects water, it will send a signal to the YoLink Relay, which will then turn off the dumb relay, consequently shutting off the pool pump.

How can I receive Alexa voice announcements when the Water Leak Sensor detects water?

What is the query status command for the Water Leak Sensor in Alexa?

Currently, Alexa supports asking "is +device name+ open/close" for the Water Leak Sensor. For example, you can ask "is the kitchen water leak sensor open" or "is the kitchen water leak sensor closed".

Why doesn't the Water Leak Sensors YS7904 show up in Google Assistant?

Unfortunately, YoLink Water Leak Sensors do not currently work with Google Assistant due to limitations imposed by Google. YoLink engineering team has attempted to link the Water Leak Sensors to Google Home, but Google does not support the necessary features for the sensor to function properly.

However, the Water Leak Sensor is compatible with Alexa and IFTTT, allowing you to create customized smart home routines and receive notifications when water is detected. If you have any further questions or concerns, please reach out to YoLink customer support for assistance.

 I received a water alert on my YoLink Water Leak Sensor, but I have already fixed the leak. The sensor is still flashing, and I am not in the same location as the sensor. If I set the device to "disabled" on the Details screen until I can clean up the water completely, will that help save battery life?

 Yes, setting the device to "disabled" on the Details screen will help save battery life. To further extend the battery life, you can also go to the Device Details screen and set the alert interval to 4 hours. This setting will be saved in the device and will reduce the frequency of the sensor reporting leaks, which can help extend the battery life. Once the water has been completely cleaned up and the sensor is dry, you can enable the sensor again and set the alert interval back to its default setting.

 My YoLink Water Leak Sensor is showing as offline, or it's reporting water leaks even when there is no water present. Is there a workaround for this issue?

Please follow the steps below to troubleshoot the issue:

1. Check the network status of the YoLink Hub to see if it's online.

2. Press the SET button on the Water Leak Sensor to check if the LED indicator has a light. If there is no light, the sensor's battery may be dead or too low. Replace the battery and press the SET button to reconnect the sensor to the hub.

3. Check the YoLink App to see if the device status has changed and if the device is online. If it's still offline, please try resetting the sensor to its factory settings.

4. Check the communication environment between the Water Leak Sensor and the YoLink Hub. Make sure there are no obstacles between the sensor and the hub, and avoid placing the sensor in semi-closed or restricted scenarios such as underground wells/pits. The placement position has a direct relationship to the signal strength.

5. If none of these steps solve the problem, please contact YoLink customer support for further assistance.

My water leak sensor probe is submerged in water but still reports "water exhausted." What can I do?

 If possible, please unplug the sensor probe cable from the sensor base and ensure that the probe is fully submerged in water. Then, use a multimeter to measure the resistance of the sensor probe by testing the top and bottom of the phono jack plug. If the resistance is over 1.2MΩ, please contact YoLink support with your shipping address and purchase invoice to receive a newer batch of sensors that support 1.8MΩ.

Can the "Water Leak Sensor 2" detect if the cable is disconnected?

No, the "Water Leak Sensor 2" is not capable of detecting if the cable is disconnected. However, if you have set up the sensor in water exhausted monitor mode and the cable is disconnected, the sensor will send an alarm and consume power.

Can the device communicate with the hub at any time, and can the hub communicate with the device at any time?

Battery-powered devices like the Water Leak Sensor 2 do not communicate with the hub in real-time. Instead, they are in armed status in real-time, meaning that they are ready to report an event to the hub immediately if one occurs. When the sensor detects water, it will report the event to the hub right away, which is an example of the sensor communicating with the hub.

Otherwise, the sensor sends a signal to the hub once every 4 hours (heartbeat signal) to confirm that it is still working correctly. This is an example of the hub communicating with the sensor.

How do I disable the beep sound of the YoLink Water Leak Sensor 2?

It is possible to disable the beep sound of the YoLink Water Leak Sensor. You can do this by going to the device details screen in the YoLink app and setting the beep sound to OFF.

 I need to make the water probe cable longer, what is the phono jack size?

It uses standard 3.5mm TRS (3-wire) connectors. Any TRS (3-wire/stereo) audio cable extension will work.

Why does my Yolink Water Leak Sensor continue to display online status even when my hub is powered off?

The status appears normal during a power outage because the hub hasn't received any data from the water leakage sensor. If there's no detection of water leakage, the hub attempts communication with the sensor every four hours. If no message is received from the sensor, the app will show as offline.

 I am trying to direct pair (D2D) the YS4909-UC valve controller and the water leak sensor, but the valve controller does not respond when the water leak sensor detects water. What can I do?

 Before attempting the D2D pairing, make sure your valve is closed and that the firmware of the valve controller is version 090e or newer. You can follow the instructions in this video for the pairing process.. If you still encounter issues after following these steps, consider reaching out to YoLink customer support for further assistance.

How can I delay the activation time for the float sensor (YS7904F)? I want it to trigger not as quickly. 

To adjust this, follow these steps:

Go to the float sensor page.

Access the device details.

Navigate to alert settings.

Disable the alarm strategy and remember to save your changes.

Once you've completed the above steps:

Go to the smart section.

Create a new automation.

Add the condition "no water detected."

Include a delay of XX seconds.

Add another condition for the float sensor and "no water detected."

Set up a notification behavior with your desired content and preferred alarm strategy.

Save your settings.