Updated Water Leak Detection - January 2026

Background

An undetected water leak in a house can result in one of the most expensive household repairs. About ten years ago, I installed a central water leak monitor for my residence and about eight remote sensors. The remote sensors detect water on the floor and notify the central monitor. The central monitor, connected to my landline, would then call my mobile number and indicate the sensor location reporting a leak. The central monitor could be configured to call out to multiple phones. This system worked flawlessly over ten years and did not have any recurring costs, other than sensor batteries.

We recently decided to terminate our landline service and just rely on our mobile phones. This anticipated change meant the landline-based leak monitor would no longer be able to call out.

Search for New Water Leak Detection System

I started looking for a replacement leak detection system and came across the Firstalert L1 WiFi Water Leak and Freeze Detector. Each remote detector communicates over WiFi to a central app. When a water leak or excess humidity is detected, the app sends text messages and emails to the registered homeowners. All configuration is performed using the app. There is no physical central hub to purchase and install - which was one of the primary features I was seeking. 

Source: Firstalert.com

Benefits:

• The FirstAlert system permits me to drop my landline. 
• There is no cost for app download or a monthly/annual subscription app fee.
• The remote sensors are easy to configure.
• Each remote has an adjustable temperature setting, which permits setting the temperature for a freeze alert. 
• Each remote has an adjustable humidity alert setting. This is needed for high humidity sensor placements, such as in a bathroom/shower area.
• The remote sensors are small and, in most cases, do not need to use the supplied cord. The cord is only required as a sensor extension. The remote is able to detect leaks without a cord.
• The app provides a date and time history of leak and high humidity detection.
• Customer service quickly replaced a remote sensor that failed a leak test upon setup.
• My homeowners insurance provides a discount for use of at least two leak detection sensors.  

Downsides: 

• The system is dependent on WiFi communication and electricity for Internet connectivity.
• The cost of an individual Firstalert leak sensor is $68, though I was able to reduce sensor cost by purchasing multiple sensor units through my home insurance partner. 
• It is unknown if app use will remain free.
• It is unknown if and when the app will reach an end-of-life date. This could be a serious issue.
• Each sensor uses two AA batteries that will need to be periodically replaced. I place a "battery installation" date label on each sensor to help remind me to proactively change the batteries in 18 months. This battery issue was similar to the previous leak detection central monitor and sensors.

The new leak detection system has been running for a few months without issue.