Smart multi-function water leak sensor MEROSS MS420 (MS420-EU)

MEROSS MS420 Smart Multifunctional Flood Sensor

The MEROSS MS420 Smart Multifunctional Flood Sensor helps protect your home from the effects of water leaks, rainwater flooding, and frozen pipes. Thanks to its large electrode surface area, adjustable probe height, and an additional 1.5-meter cable, it can also monitor hard-to-reach areas—such as the space under a washing machine or around pipes—as well as water levels in tanks. The sensor emits an audible alarm at 100 dB and allows you to set the conditions under which the alarm should be triggered. The device features IP65 water and dust resistance, and thanks to its energy-efficient Bluetooth connectivity, it can operate for up to 4 years on a single battery.

Precise water detection and adjustable probe height

The large surface area of the electrodes allows for the detection of even small amounts of water, enabling quick detection of minor leaks. The adjustable probe height allows you to adapt the detection method to the surrounding conditions. At a low setting, the sensor reacts to small amounts of water, while a higher setting helps prevent false alarms caused by temporary surface moisture. The device can also detect a lack of contact with water, so it can monitor water levels in aquariums, tanks, or animal drinking fountains and alert you when the level drops.

Additional Probe for Hard-to-Reach Areas

The included 1.5-meter probe cable allows you to extend the monitoring area without having to place the entire sensor in a flood-prone location. The small probe fits even in narrow gaps, such as under a washing machine or dishwasher, near pipes and drains, or behind furniture. This allows you to monitor areas where a leak might go unnoticed for a long time. The included adhesive tape makes it easy to attach an additional probe in the desired location.

Smart notifications and fewer false alarms

The sensor detects leaks, monitors rainfall, and warns of the risk of freezing. It also allows you to combine different conditions—such as the presence of water and low temperatures—so that the alarm is triggered only in specific situations. The ability to set a detection delay reduces the number of false notifications caused by brief contact with water. In the event of a threat, the device activates a loud alarm, allowing you to respond more quickly and limit potential damage.

Durable design and up to 4 years of operation

The IP65-rated housing protects the device from dust and water jets, making the sensor suitable even for areas exposed to moisture. The operating temperature range of -20°C to 60°C allows it to be used in a variety of conditions. Bluetooth Low Energy (BLE) technology reduces power consumption, and the replaceable CR123A battery provides up to 4 years of operation. The device is compatible with smartphones running Android 8.0 or later and iOS 13 or later.

Included in the package

• MEROSS MS420 Smart Flood Sensor
• Cable with an additional probe
• CR123A battery
• Battery compartment opening tool
• User manual