relay

Zooz ZEN51 Dry Contact Relay

mid local: excellent Z-Wave

Price: $37.95 verified Sep 5, 2026
HA fit: excellent
Works offline: yes
Setup: advanced
Hub needed: yes

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Zooz ZEN51 Dry Contact Relay - Tiny behind-the-wall relay that makes an existing switch Z-Wave smart without replacing it

Quick verdict

The ZEN51 hides behind your existing switch and makes it smart. Your wall plate stays the same, your spouse stays happy, and Home Assistant gets Z-Wave control. Wiring is simple if you are comfortable with electrical work, but this is not a beginner device.

Standout: Tiny behind-the-wall relay that makes any existing switch Z-Wave smart without replacing the switch itself.

Notes last checked May 31, 2026.

Compatibility snapshot

Home Assistant excellent

Apple Home none

Google Home none

Alexa none

Works offline yes

Setup advanced

Extra hub needed yes

Power hardwired

Local control facts

Home Assistant: zwave_js integration, Local Push (home-assistant.io, checked Sep 10, 2026)
Z-Wave JS: in the device database, listed as Zooz ZEN51 (Dry Contact Relay) (github.com, checked Sep 10, 2026)

Why it stands out

tiny form factor fits behind most switches or inside junction boxes
makes any dumb switch smart without replacing the switch itself
Z-Wave 700 series with Long Range support for improved range and reliability

Reasons to hesitate

wiring behind an existing switch requires electrical confidence and is not plug-and-play
single relay only, so if you need two, look at the ZEN52
tight fit in shallow or crowded gang boxes

Best for

making existing dumb switches smart without changing the switch plate
adding Z-Wave control to devices like garage doors or low-voltage systems

Avoid if

you are not comfortable wiring behind a switch or in a junction box
you want dimming, since this is on/off relay only

Privacy and local-control notes

Pure Z-Wave device. No cloud, no data collection. Now available with Z-Wave Long Range in some regions.

Home Assistant support: supported · integration path: Z-Wave JS.

Buying reality check

Price notes: Affordable for a Z-Wave 700 relay. Cheaper than replacing the whole switch if you like your existing hardware.

One verified price read so far: $37.95 at amazon on Sep 5, 2026.

Compare side by side: see relay comparisons →

Verified against

The compatibility notes above have not been through the source audit yet. The manufacturer's page is here; the notes were last checked May 31, 2026.

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