Last updated: August 9, 2021

Welcome to our big product test 2022. Here we present all the water detectors we have tested in detail. We have compiled detailed background information and added a summary of customer reviews on the internet.

We would like to make your purchase decision easier and help you find the best water detector for you.

You will also find answers to frequently asked questions in our guide. If available, we also offer interesting test videos. Furthermore, you will also find some important information on this page that you should definitely pay attention to if you want to buy a water detector.


  • Small, inexpensive water detectors in households already help to protect against major water damage. They can be placed especially in places where no obvious water damage can be seen.
  • The small household gadgets are now available everywhere and with a WLAN function they can be connected to the Smarthome network, so you also get a notification outside the house about what is happening at home.
  • The water sensors are installed directly on the device or on an external cable. If you are considering buying a water detector, you should pay attention to the area of application and the additional functions.

The Best Water Detector: Our Picks

Guide: Questions you should ask yourself before buying a water detector

What is a water alarm?

A water alarm is an electronic device that triggers an alarm when the liquid sensor comes into contact with water.

These devices are very useful in homes (especially basements) to protect against water damage and mould growth caused by leaking water pipes, broken plumbing fixtures, a blocked sewer or drain caused by a severe thunderstorm.

Those who consider buying a water detector will prevent major water damage at home. (Image source: Kaboompics)

Slow leaks from appliances and plumbing fixtures often go unnoticed. Excess moisture and water from a slow leak can severely damage the floors and walls of the home.

A water detector already informs you when there is a moisture problem.

How does a water detector work?

There are two types of water detectors, passive and active. The passive detector uses a 9-volt battery. The water detector has a moisture sensor that has three electrons on the bottom and measures the electrical resistance.

An alarm is triggered when this sensor gets wet. Damp places or high temperatures can reduce the battery life. Therefore, the detector should be checked regularly to make sure it is working properly.

Active water detectors can operate a single device or control the whole house. This system also generates an alarm and automatically shuts off the water supply.

Who is a water detector suitable for?

In principle, a water detector is suitable for everyone. The many benefits make the water detector one of the most popular smart home gadgets available.

Above all, however, a water detector is suitable for households that do not want to spend money on high water damage.

A water detector can prevent major damage that can be caused by flood water in any home.

When one thinks of the consequences of flooding, the first thing that comes to mind is property damage, but physical damage can also occur. People whose health is at heart should therefore also get a water detector.

Even if the situation is not serious and you quickly drain water and dry the floor, walls or furniture, the risk of mould growth is very high.

Moisture causes mould spores to multiply within 24 hours of a leak. They pollute the air and threaten human health.

Sneezing, allergies and even asthma can be triggered by fungi. Mould is very difficult to remove because the spores spread wherever there is moisture.

The video below emphasises once again why it pays to buy a water detector:

How much does a water detector cost?

Depending on the desired extra functions besides the simple notification of too much water, the quality and the housing, the prices vary between 10 and 60€.

Price Extras
Up to 20€ Siren, 85 dB, 9 V battery-operated, made of plastic
Up to 40€ Smart Home capable, 1.5 V battery-operated, 77dB, made of plastic, temperature-resistant
Up to 60€ Smarthome capable, mains and battery-operated, 90 dB, remote access possible, temperature-resistant

The other purchase criteria that influence the price can be found further down in this article.

Decision: What types of water detectors are there and which is the right one for you?

If you want to get a water detector, there are several types to choose from:

  • Battery-operated water detector
  • Water detector with cable

The use of the different types of water detectors has its advantages and disadvantages.

Depending on what you prefer and what you want to use the water detector for, a different type is suitable for you. In the following section, we would like to make the decision easier for you.

What are the features of a battery-powered water detector and what are its advantages and disadvantages?

Battery-operated models, as the name suggests, only work with a battery and have the advantage that they can be installed anywhere.

You can place this device on the floor or attach it to something with an adhesive strip and it is ready to use.

In the case of a battery-operated water detector, the sensor is located in the actual device; instead of the sensor, so-called sensors can also be attached.

  • Sensor directly on the device, no installation effort
  • Flexible placement of the water detector
  • Audible alarm when water is detected
  • Not very flexible in installation
  • High water level damages the device
  • May be in the way

What distinguishes a water detector with a cable and what are its advantages and disadvantages?

The water detectors that come with a cable must be mounted on the wall, on a cabinet or on another object.

They guarantee stability if everything is mounted correctly. It is important to ensure that the cable is long enough.

This model has a cable attached to it, the sensor that will later alert you in case of contact with water is built into the cable. The cable must touch the ground so that the sensor can fulfil its purpose.

  • Suitable for large areas
  • Detects water along the entire length of the cable
  • Audible alarm when water is detected
  • Unit remains undamaged when water level is high
  • No need to change batteries
  • Not very flexible in terms of installation
  • If the cable stops working, the device cannot give a signal
  • There must be a socket nearby
  • The devices with an external sensor are usually more expensive

Buying criteria: Use these factors to compare and test water detectors

In the following, we would like to show you which factors you can use to compare and evaluate water detectors. This will make it easier for you to decide whether a particular water detector is suitable for you or not.

In summary, these are:

  • Material
  • Mounting
  • Sensor
  • Volume
  • WLAN
  • Additional functions

In the following paragraphs, we will explain to you what is important in the individual criteria.


Most water detectors are made of plastic, but there are also models made of aluminium. When buying, it is important to note where the device will be used and that the water detector does not have any dents.


Before buying, you should think about where the water detector will be installed.

Depending on the location to be served, it is important that the supplier also supplies the material necessary for mounting and that mounting devices are taken into consideration.


It is important to remember that for large areas, the sensor should be attached to the cable. The so-called measuring sensors are located on the cable.

A higher number of sensors also ensures a more reliable signal in the event of water damage. The longer and the more sensors there are on the water detector, the larger the monitoring area.


The water detector only fulfils its purpose if it emits an appropriate sound that is perceived by a person in the household so that no damage occurs.

The alarm should be at least 85 decibels loud so that it can be heard throughout the house.


Water detectors with WLAN function enable the device to be included in the Smart Home network and controlled from a smartphone.

So if you have a "smart" water sensor, it can send out smartphone notifications when someone is home or not.

The smartphone can even be used to control the water detector via a WLAN function and send push notifications. ( / geralt)

Additional functions

In addition to flood protection, some water detectors include temperature alerts so you don't have to worry about frozen pipes and extreme temperatures.

Some models can also control humidity.

There are also water detectors that have LEDs that light up when the unit detects a leak or has battery or connection problems.

Important facts about water detectors

This section contains frequently asked questions that consumers have after buying a kitchen radio.

How and where do I install a water detector?

It is best to install a water detector on household appliances that are operated with water. For example, under a dishwasher, where water often leaks unnoticed.

The washing machine, which is usually located in the basement, could also cause water damage.

The washing machine or the dryer are usually left unattended and something can happen very quickly, which is why the water detector can help to prevent major damage.

Defective showers, bathtubs and toilets, however, are the number one risk of water damage.

Under the shower or bathtub, it is difficult to see if a pipe has burst, and when you do, it is usually already too late.

Therefore, you should definitely consider installing a water detector under the shower.

Did you know that the bathroom is the most popular place for a water detector?

There are several areas of application for water detectors in the bathroom. There are water pipes to the sink, bathtub and shower.

What should I do if my water detector stops working?

Water detectors can stop working for a variety of reasons.

Problem Solution
Unit does not give alarm on contact with water Check sensor to see if it is perhaps blocked, if the external sensor is broken. If nothing helps, the unit must be replaced.
Battery is flat put new batteries in the unit or check that everything is plugged in correctly

If the listed problems are still not solved, it is advisable to check the unit for external damage and, in case of major defects, to take it to a specialist or refer to the unit's warranty.

How do you maintain a water detector?

Often ignored or forgotten, water detectors are not maintenance-free and must be serviced regularly.

Typically, systems need to be tested every 3 or 6 months, depending on the system installed and the environment in which the system is installed.

People often forget that the water leak detection system was installed for a reason.

Only by calling in a leak testing specialist to carry out system checks and maintenance can you be sure that your water detector is providing adequate protection for your home.

You can see how to turn a smoke detector into a water detector in this video:

Image source: / Pornchai Jaito