Where to put water leak sensors and alarms
Short answer: Put leak sensors on the floor where water would appear first: beside or under the water heater, washing machine, sump pit, water softener or filter, dishwasher, refrigerator ice-maker line, and under sinks and toilets. The sensor should touch the floor at the lowest point nearby.
Step by step
- List water sources. Water heater, washer hoses, sump pit, under-sink plumbing, toilets, ice-maker and dishwasher lines, softener or filter housings.
- Place at the low point. Floors are rarely level. Put the sensor where water would pool, usually toward a wall or drain.
- Choose alerts. Local alarms sound in the room; Wi-Fi models can alert your phone when you are away.
- Test regularly. Test per the maker's instructions and replace batteries on schedule.
Leak sensors and alarms
- DC Floor Water Leak Sensor — 30 Foot — $30.02
- DC Floor Water Leak Sensor — 6 Foot — $17.91
- Leak Blaster™ High-Output Water Leak Alarm, 10 Year Battery Life, 125dB Horn — $187.42
- Level Sense PRO- Wi-Fi Enabled Sump Pump, Water Heater, Temperature, Humidity, and Leak Detector — $247.95
- Level Sense Sentry — Leak Sensor — $133.48
Common questions
Does a leak sensor shut off water?
Only if it is part of a shutoff system. The sensors and alarms we list warn you; they do not close a valve.
How much water triggers a leak sensor?
It depends on the sensor; most respond when water bridges their contacts on the floor.
Can one alarm cover several places?
Some alarms accept remote sensor cables so one unit can watch more than one spot. Check each listing.
Related categories: Sump & Effluent Pumps & Alarms. General information only; follow the equipment maker's instructions and local codes. Updated 2026-11-14.