Heiman HS2WD Smart Siren Review: A Zigbee Alarm With 12 Hours of Battery Backup
A 95 dB indoor siren with a red LED strobe that keeps working during a power cut, for SmartThings and Home Assistant setups.
The Heiman HS2WD is a Zigbee siren that turns any sensor trigger into a loud, visible alarm: 95 dB of sound plus a red LED light, controlled from SmartThings or Home Assistant through a Zigbee hub. Its most valuable spec is the built-in battery, which keeps it sounding for up to 12 hours after mains power is lost, which is exactly the scenario a burglar creates by cutting power. It is an indoor unit with no weather rating, and it has no tamper switch, so treat it as an audible deterrent inside the house rather than a full alarm bell box.
- SmartThings and Home Assistant alarms
- DIY security setups
- Water leak and smoke sensor alerts
- Indoor deterrence
Pros
- 95 dB siren, loud enough to be unmissable indoors
- Red LED light as a visual alarm alongside the sound
- Built-in battery keeps it sounding for around 12 hours after a power cut
- Mains powered for permanent installation
- Works with Samsung SmartThings and Home Assistant
- Driven by automations, so any sensor can trigger it
- Compact at 80 x 80 x 32 mm
Cons
- Requires a Zigbee hub, with no Wi-Fi or other radio option
- No tamper switch or vibration sensing
- Google Home and Apple HomeKit support is not documented, and Alexa only sees a switch
- No IFTTT or Matter support
- Indoor only, with no weather resistance rating
- No voice prompts and no presence simulation
- Tone options, sound duration and light brightness are not documented
Who is the Heiman HS2WD for?
A siren is the piece that makes a DIY alarm system feel real. Sensors and automations can send a phone notification, but only a loud noise gets attention when you are at home or asleep, and only a noise makes an intruder leave. This one is built for Zigbee systems specifically, and its documented integrations are Samsung SmartThings and Home Assistant, which are the two platforms most DIY alarm builds run on. Beyond security, it also works as the audible output for any critical automation: a water leak sensor, a smoke sensor relayed through your hub, or a freezer temperature alert.
What it does
Sound output is 95 dB, loud enough to be unmissable indoors, and a red LED provides the visual half of the alarm, which matters both for people who might not hear it and for identifying which device triggered. Automations drive it, so any rule in your platform can start and stop the siren. It is mains powered with a built-in rechargeable battery good for around 12 hours, so it continues to sound if the power is cut, a scenario where a mains-only siren simply goes quiet. The 80 x 80 x 32 mm body is small enough to mount discreetly in a hallway or stairwell.
What to know before you buy
It needs a Zigbee hub: there is no Wi-Fi, Bluetooth, Z-Wave or Thread option. Alexa has no siren device type, so a hub publishes it as a plain switch, and Google Home and Apple HomeKit support is not documented for this model, so plan around SmartThings or Home Assistant. IFTTT and Matter are unsupported. There is no tamper switch, so the siren cannot report being opened or removed, and no vibration sensing, which are the features that distinguish an alarm-grade sounder. It has no weather resistance rating, so it is indoor only, and there is no voice prompt capability and no presence simulation. Tone options, sound duration and light brightness are not documented.
Is the Heiman HS2WD worth it?
For a Zigbee alarm build, a siren with its own battery is worth more than the decibel figure suggests, since it covers the power-cut case that catches out cheaper sounders. It sits at a mid-range price for the category. Weigh it against sirens with tamper protection and outdoor ratings if you want an exterior bell box, and check that your platform is SmartThings or Home Assistant before buying, since the voice assistant paths are not confirmed.
Frequently asked questions
Does the Heiman HS2WD need a hub?
Yes. It is a Zigbee device, so a Zigbee hub is required. Samsung SmartThings and Home Assistant are the documented platforms.
Does it keep working during a power cut?
Yes. It has a built-in battery rated for around 12 hours, so it can still sound if mains power is lost.
How loud is it?
95 dB, with a red LED light that flashes alongside the alarm.
Can it be installed outdoors?
No. It has no weather resistance rating, so it is an indoor siren.
Does it detect tampering?
No. There is no tamper switch and no vibration sensor, so it will not report being opened or removed.


