sensor

ThirdReality Water Leak Sensor

budget local: excellent Zigbee

Price: $18.99 verified Nov 2, 2026
HA fit: good
Offline: yes
Setup: easy
Hub needed: yes

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Quick verdict

Cheap, simple, and it works - that's all you really need from a water leak sensor. Scatter a few under sinks, behind the washing machine, and near the water heater. Zigbee means it runs fully local through Home Assistant with no cloud or subscription.

Standout: Cheap Zigbee leak detection with a 120 dB on-board alarm that sounds even with the hub or internet down.

Notes last checked May 31, 2026.

Compatibility snapshot

Home Assistant good

Apple Home none

Google Home none

Alexa okay

Works offline yes

Setup easy

Extra hub needed yes

Power battery

Local control facts

Home Assistant: zha integration, Local Polling (home-assistant.io, checked Oct 10, 2026)

Why it stands out

very affordable water leak detection
built-in 120 dB alarm sounds on the sensor itself, with no hub, coordinator or internet needed
solid Zigbee compatibility with zigbee2mqtt and ZHA
long battery life on 2x AAA batteries

Reasons to hesitate

detection and a local alarm only - it cannot drive a water shutoff valve
requires a Zigbee coordinator for Home Assistant use

Best for

budget water leak monitoring under sinks, water heaters, and washing machines
Zigbee Home Assistant setups needing reliable leak alerts

Avoid if

you want an all-in-one leak detection plus automatic shutoff system
you have no Zigbee coordinator

Privacy and local-control notes

Pure Zigbee sensor with no cloud dependency. Fully local operation through zigbee2mqtt or ZHA.

Home Assistant support: supported · integration path: zigbee2mqtt / ZHA.

Buying reality check

Price notes: Very budget-friendly. Buy multiples to cover every leak-prone spot.

Verified price reads: lowest seen $14.99, latest $18.99 on Nov 2, 2026.

Nov 2, 2026$18.99amazon
Oct 31, 2026$20.99amazon
Oct 24, 2026$20.99amazon
Oct 17, 2026$20.99amazon
Oct 10, 2026$20.99amazon
Oct 8, 2026$14.99amazon
Oct 7, 2026$14.99amazon
Oct 6, 2026$14.99amazon

Compare side by side: see sensor comparisons →

What changed for this product

Oct 10, 2026 · Brief

Black Friday smart home deals for Home Assistant: the prices to beat

Black Friday 2026 smart home deals for Home Assistant and local-control homes: the lowest price I've recorded for 100+ Zigbee, Z-Wave, Matter and Wi-Fi devices.

From the change log and the news briefs that name this product.

Verified against

Third Reality: Zigbee Water Leak Sensor (live product page (200) after both earlier URLs returned 404) · checked Sep 7, 2026

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Buying guide for this category

Still deciding between products? Start with the broader category guide.

Best Zigbee sensors for Home Assistant, plus Z-Wave and other local picks →

Articles that mention this product

Black Friday smart home deals for Home Assistant: the prices to beat

Black Friday 2026 smart home deals for Home Assistant and local-control homes: the lowest price I've recorded for 100+ Zigbee, Z-Wave, Matter and Wi-Fi devices.

Read article →