(Editorial note: Since publication, Shelly has confirmed that the Flood Sensor model referenced in this article has been discontinued. An updated version is expected to be released soon. We will update this article as more information becomes available.)

As temperatures drop, the risk of leaks, burst pipes and unnoticed water damage rises for homes, rentals and commercial spaces. Many properties are left unattended during the holiday period, making it harder to spot issues before they cause serious structural and electrical damage. A smart flood sensor provides an extra layer of protection, using WiFi connectivity to send alerts the moment water is detected, so action can be taken quickly even when you are away.

The Shelly Flood Sensor is a compact, smart flood sensor designed to protect property while you are away, combining a sensitive water probe, WiFi leak detector functionality and simple installation without the need for a dedicated hub. Paired with a smartphone or wider smart home system, it offers a straightforward way to keep an eye on critical areas such as boiler cupboards, bathrooms, kitchens and utility rooms, helping to prevent costly and disruptive water damage.

Why water leak detection matters in winter

Winter brings a higher risk of problems such as frozen pipes, boiler faults and appliance failures, all of which can lead to sudden water leaks. When temperatures drop, pipework in lofts, basements and unheated spaces is more vulnerable to cracking or bursting, and even small leaks can quickly turn into significant issues if they are not noticed in time. For many households and landlords, the combination of cold weather and increased heating and hot water usage makes winter one of the peak periods for water leak risk.

At the same time, homes and rental properties are frequently left empty during winter travel and holiday periods, which increases the likelihood that leaks will go unnoticed for hours or even days. Hidden water can seep into floors, walls and insulation, causing structural damage, electrical hazards and mould growth that is costly and disruptive to repair. Real time water leak detection provides a crucial early warning, allowing owners and property managers to respond quickly, limit property damage and avoid expensive insurance claims, even when they are away from home.

How the Shelly Flood Sensor works

The Shelly Flood Sensor operates as a WiFi flood sensor, connecting directly to a home or office network to deliver instant mobile notifications whenever water is detected. Its built in probe reacts quickly to even small amounts of moisture, making it a reliable smart leak detection device for kitchens, bathrooms, boiler rooms and utility areas. In addition to water sensing, the device includes temperature monitoring to provide early warnings of freeze risk during colder months.

Designed for straightforward installation, the sensor is fully battery powered and housed in a compact, low profile enclosure that fits easily under appliances, along pipework or in other tight locations where leaks often occur. No hub or dedicated gateway is required, keeping the setup simple and reducing overall system complexity. Users can adjust alert preferences, set up automation triggers and connect the sensor with other smart devices to activate lights, alarms or notifications when an issue is detected.

The Shelly Flood Sensor integrates smoothly with popular smart home platforms including Home Assistant, Google Home and Amazon Alexa. This interoperability allows it to function as part of a broader water leak alert system, supporting flexible monitoring and automated responses across different property types.

Technical specifications

• Battery type: 3V DC CR123A
• Battery life: Up to 18 months of operation
• Electrical consumption: Static ≤ 5μA, Awake ≤ 250mA
• Temperature measurement range: -40°C to 60°C with ±1°C accuracy
• Working temperature: -40°C to 60°C
• Dimensions: 70 x 19 x 19 mm (H x W x L)
• Radio protocol: WiFi 802.11 b/g/n
• Radio signal power: 1mW
• Frequency range: 2400 – 2500 MHz
• Operational range: Up to 30 metres outdoors, up to 15 metres indoors

Key features and use cases

The Shelly Flood Sensor delivers a set of practical features designed to support smart home protection and reliable monitoring while you are away. Its high sensitivity water detection provides early leak identification, sending immediate alerts when liquid is detected to help prevent costly damage. The integrated temperature sensor offers continuous monitoring of environmental conditions, giving early warnings of freeze risk during colder months.

With extended battery life and a compact, wireless design, the sensor fits easily under sinks, beside boilers, near appliances or in tight spaces where leaks often occur. Its seamless WiFi connectivity allows for remote monitoring without additional hubs, and the device can operate independently or as part of a wider automation system. For added flexibility, it supports voice assistant platforms and offers an HTTP control protocol, enabling advanced users to build custom automation or REST API integrations.

• Early leak detection: Immediate alert system for liquid presence, helping prevent water damage.
• Temperature monitoring: Continuous tracking of environmental temperature with precise measurement.
• Wireless connectivity: Integrates with existing WiFi networks for remote monitoring and alerts.
• Extended battery life: Power efficient design providing up to 18 months of maintenance free operation.
• Dual operation modes: Works independently or as part of a wider smart home automation setup.
• Voice control compatibility: Supports major voice assistants for convenient operation.
• HTTP control protocol: Allows custom integrations and advanced control via REST API.

These capabilities make the Shelly Flood Sensor suitable for a wide variety of flood sensor use cases. It provides dependable home protection during holidays, ideal for rental properties, AirBnB homes and second residences that may remain unoccupied. It is equally effective in basements, bathrooms, laundries and kitchens where leaks are more common, as well as in offices or workshops that are left unattended outside working hours. Whether installed in residential or managed properties, the Shelly Flood Sensor helps ensure continuous monitoring and improved peace of mind.

How to buy and key takeaways

The Shelly Flood Sensor model referenced in this article has now been marked as end-of-life (EOL) by distributors. A next-generation version is expected, although no release date has been announced. In the meantime, customers looking for smart home water-leak protection or similar IoT devices can browse alternatives via Parts To You, which offers fast UK delivery and a wide selection of automation products suitable for homes, rentals and managed properties.

Reliable leak detection remains one of the most effective ways to minimise the impact of unexpected water damage. Even a small leak can lead to significant repair costs if left unnoticed, particularly during colder months or periods when properties are left unoccupied. Smart sensors with instant alerts and flexible placement help protect high-risk areas such as under sinks, near boilers, behind appliances and in crawl spaces.

For alternative smart home devices, visit Parts To You: