Water leak detectors and automatic shut-off valves

Why they are worth having

Water damage is one of the most common and costly kinds of home insurance claim in Canada. The amount of damage depends mostly on time. A supply hose that splits while you are standing beside it soaks a floor. The same hose splitting on the first day of a two-week holiday can wreck three storeys.

Leak detection shortens the time between the leak starting and someone, or something, turning the water off.

Three levels of protection

1. Standalone alarms

A small battery-powered puck or box with metal contacts on the bottom. When water bridges the contacts, it sounds a loud alarm.

• Very cheap, no installation
• Useful only if someone is home to hear it
• A good start for under sinks and by the water heater

2. Connected sensors

The same idea, linked to your home Wi-Fi or a hub. They send an alert to your phone and often monitor temperature as well, warning you if the house is heading towards freezing.

• You find out wherever you are
• Somebody still has to act: you, a neighbour with a key, or a plumber
• Depend on working Wi-Fi and power to the router, unless they have a cellular or battery backup
• Batteries need replacing, and most apps warn you when they are low

3. Automatic shut-off valves

A motorised valve installed on the main water line, just after the meter and main shut-off. It closes when triggered. There are two ways of triggering it.

Sensor-triggered. Leak sensors round the house signal the valve to close when any of them gets wet. It protects only where there is a sensor.

Flow-monitoring. The device measures water flow and pressure at the main line and learns the household’s normal pattern. It closes the valve when it sees something abnormal, such as water running continuously for too long, and many can detect slow leaks by running a small pressure test at night. It covers every pipe downstream, including those inside walls.

Many systems combine both. Most can be closed and opened from a phone, and have a manual override.

Where to put sensors

Wherever water is connected or collects:

• Beside the water heater
• Behind or beside the washing machine
• Under the kitchen sink and by the dishwasher
• Behind the fridge, if it has an ice maker or water dispenser
• Beside each toilet
• Under bathroom vanities
• By the furnace, if it has a humidifier or a condensate pump
• Near the air conditioner’s indoor unit and drain line
• Beside the sump pit, set so that it triggers before the pit overflows
• Near the floor drain
• At the base of basement windows or other known leak spots
• Under a water softener or filter system
• Under an aquarium

Place them on the floor at the lowest point, where water will reach first. Some have a cable sensor that can be run along a wall or under an appliance.

What to look for when buying

• Certification for use in Canada, and for valves that touch drinking water, certification to the relevant plumbing and drinking water standards
• The right size for your main water line
• Battery or backup power so that the valve can still close in a power cut
• A manual override
• Temperature alerts for freeze protection
• Loud local alarm as well as phone alerts
• Expandable with more sensors
• App alerts to more than one person
• No reliance on a single cloud service for the basic shut-off function, where possible
• Compatibility with wells, irrigation systems, fire sprinklers and hot water heating, if you have them

Installation

• Standalone and connected sensors need no tools
• An automatic shut-off valve is cut into the main line and should be installed by a licensed plumber. It needs a power outlet nearby and space on the pipe after the main shut-off.
• If the home has a residential fire sprinkler system fed from the same line, the valve must not be able to shut off the sprinklers. Get professional advice on where it goes.
• In a condo, ask the corporation before altering the plumbing. Some buildings install unit shut-off systems themselves.

Living with a shut-off valve

• Flow-based systems take a few weeks to learn your patterns and may shut off during an unusually long shower or while filling a pool until you adjust the settings
• Use the away mode when you travel, which makes the system more sensitive
• Test it twice a year: wet a sensor and confirm the valve closes
• Exercise the valve periodically so that it does not seize. Many do this automatically.
• Replace sensor batteries on schedule

What they do not do

• They do not stop water that arrives from outside: sewer backup, ground water, roof leaks or surface flooding. A sensor will warn you, but closing the supply does nothing.
• They do not drain the water already in the pipes or the water heater
• They do not replace maintenance: old supply hoses, corroded shut-offs and ageing water heaters still need attention
• They do not replace having someone check the house when you are away, which many insurance policies require in winter

Insurance discounts

Some Canadian insurers offer a premium discount for a professionally installed automatic shut-off system, and a few give sensors to policyholders or require a shut-off device after a water claim or in certain buildings. The discounts and the devices that qualify vary. Ask your broker before you buy, and send proof of installation.

Low-cost steps that matter as much

• Know where the main shut-off is and make sure it turns
• Replace rubber washing machine hoses with braided stainless steel
• Replace plastic toilet and tap supply lines and old shut-off valves
• Replace a water heater before it fails, and put a pan under it where there is a drain
• Shut off the main when you travel

More: burst pipe and water damage.