Best simple alarm in water alarms and leak sensors
A simple battery water alarm with a 110 dB siren and a sensor on 6 ft of wire you can drop into the sump pit. No app and nothing to set up, but no alert when you're away.
Our score: 7.4/10 out of 10Researched, not lab-tested
- Connection
- None (local alarm only)
- Alarm loudness
- 110 dB
- Battery
- 9 V
- Warranty
- 5 years
Is it right for you?
Pros
- 110 dB siren
- Senses about 1/32 in of water
- Sensor on 6 ft of wire, extendable to 100 ft
- Runs on one 9 V battery and draws power only while sounding
- 5-year limited warranty
Cons
- No phone alert: someone must be home to hear it
- No low-battery warning described: date the battery yourself
- Warranty claims mean returning it to the factory with proof of purchase
- No safety listing shown on the maker's product page
- Best for
- A cheap first line of defence next to the sump pit, water heater or washer, in any home where someone is usually in.
- Not for
- Cottages, rentals or anyone away from home who needs an alert on their phone.
Our verdict
The Watchdog Water Alarm is about as simple as leak protection gets. Snap in a 9 V battery, set it down, and it sounds a 110 dB alarm when its sensor touches about 1/32 in of water. The sensor hangs on 6 ft of wire, which can be spliced out to 100 ft, so the alarm can sit on a wall while the sensor watches the top of the sump pit.
Glentronics says it draws power only while sounding, and gives a five-year warranty. Its weakness is the one every standalone alarm shares: it can’t tell you anything when you’re out. The manual also describes no low-battery warning, so write the battery date on it. For alerts on your phone, pair it with the YoLink leak sensor kit, or compare the water alarms and leak sensors we compare.
Setting it up
The battery snaps onto a connector inside the right-side compartment. The alarm can stand on the floor or hang on a wall with the sensor wire run to the sump. Replace the battery after any long alarm or before its expiry date, and mark that date on a piece of tape on the alarm.
Safety: When it sounds, check where the water is coming from before you go near it. If the basement is already flooded, stay out of the water while anything electrical could be live and ask your electric utility to cut the power; our guide to the first hours after a basement floods goes step by step.
Specs
Basement Watchdog Water Alarm BWD-HWA
Alerts
| Connection | None (local alarm only) |
|---|---|
| Phone alerts | No |
| Shuts off the water | No |
| Alarm loudness | 110 dB |
| Freeze alert | No |
| Hub needed | No |
| Alarm | Yes |
Other details
| Battery | 9 V |
|---|---|
| Warranty | 5 years |
Maker’s figures, checked 4 Nov 2026.
Basement Watchdog Water Alarm questions
How long is the sensor wire?
6 ft. The manual says up to 100 ft of wire can be spliced in to reach a remote spot, such as the sump pit from a wall nearby.
Does it warn me when the battery is low?
The manual describes no low-battery warning. Replace the 9 V battery after a long alarm or before its expiry date, and write the date on tape on the alarm.
Will it alert my phone?
No. It is a local alarm only. For phone alerts you need a connected sensor, such as a YoLink kit with its hub.