Outcome
This companion comparison post compares Smoke Detector and Alarm Trigger to the top live alternatives found on April 10, 2026, including current Amazon and Alibaba checks.
Source Device
The Kidde SM120X Interconnect Accessories Smoke Relay Module is designed to integrate traditional interconnected Kidde in-home smoke detectors with a smart home system like Home Assistant. It sends smoke alarm conditions to Home Assistant and allows for manual triggering of auxiliary warning devices by switching connected device power when a smoke/heat interconnect signal is received. It is used with multiple station alarms and detectors, specifically Kidde Fyrnetics devices.
Top Alternatives
- HS1SA-E Zigbee Smoke Detector: This device is a standalone smart smoke detector that directly integrates with Home Assistant via Zigbee, offering comprehensive smoke detection and reporting. It provides advanced features like real-time smoke levels, temperature, remote test, and remote mute, which aligns with the 'sends smoke alarm conditions to Home Assistant' and 'manual triggering of smoke alarm' (interpreted as remote control of its own alarm or related actions) aspects of the source device. It offers a modern, integrated smart smoke detection solution.
- SMCO410 Z-Wave Plus Smart Smoke & CO Alarm: This is a direct replacement smart smoke and carbon monoxide detector that integrates with Home Assistant via Z-Wave. It offers both smoke and CO detection, a loud siren, and a 10-year battery, providing a comprehensive safety solution. While it cannot be remotely silenced via Z-Wave, it fulfills the core detection and reporting functionality to Home Assistant, similar to how the Kidde SM120X reports conditions.
- ZEN55 DC Signal Sensor: This device is a direct functional alternative to the Kidde SM120X, acting as a bridge to make existing interconnected hardwired smoke and CO detectors 'smart'. It translates their low-voltage trigger signals into Z-Wave commands for Home Assistant, and crucially, it includes an optional 120V relay output to control auxiliary devices like a siren or lights, directly matching the SM120X's ability to connect auxiliary warning devices and allowing for 'manual triggering' of these connected devices via Home Assistant.
Comparison Matrix
| Category | Smoke Detector and Alarm Trigger | HS1SA-E Zigbee Smoke Detector | SMCO410 Z-Wave Plus Smart Smoke & CO Alarm | ZEN55 DC Signal Sensor |
|---|---|---|---|---|
| Features | Source device | ★★★★☆ | ★★★★☆ | ★★★★☆ |
| Interoperability | Source device | ★★★★★ | ★★★★☆ | ★★★★★ |
| Setup Ease | Source device | ★★★★☆ | ★★★★☆ | ★★★☆☆ |
| Cloud Dependency | Source device | ★★★★★ | ★★★★★ | ★★★★★ |
| Vendor Trust | Source device | ★★★★☆ | ★★★★☆ | ★★★★☆ |
| Overall | Source device | ★★★★☆ | ★★★★☆ | ★★★★☆ |
Pricing And Availability
| Device | Amazon Price | Alibaba Price |
|---|---|---|
| HS1SA-E Zigbee Smoke Detector | N/A | Approximately $15-$25 USD (often in bulk) |
| SMCO410 Z-Wave Plus Smart Smoke & CO Alarm | Approximately $50-$70 USD | N/A |
| ZEN55 DC Signal Sensor | Approximately $35-$45 USD | N/A |
Operator Notes
- The 'manual triggering of smoke alarm' feature of the source device (Kidde SM120X) is interpreted as the ability to either trigger its own alarm sound (for smart detectors) or trigger auxiliary devices (for relay modules).
- Prices and availability are subject to change and reflect information found as of April 10, 2026. Alibaba prices often reflect bulk purchasing.
Source URLs
HS1SA-E Zigbee Smoke Detector | Official: https://www.heimantech.com/product/hs1sa-series-smoke-alarm/
HS1SA-E Zigbee Smoke Detector | Home Assistant: https://community.home-assistant.io/t/heiman-smoke-alarm-hs1sa-e-new-features-in-zha-and-z2m/858485
HS1SA-E Zigbee Smoke Detector | Amazon: N/A
HS1SA-E Zigbee Smoke Detector | Alibaba: https://www.alibaba.com/trade/search?fsb=y&IndexArea=product_en&keywords=Heiman+HS1SA-E+Zigbee+smoke+detector
SMCO410 Z-Wave Plus Smart Smoke & CO Alarm | Official: https://www.firstalert.com/products/smoke-carbon-monoxide-alarms/smart-alarms/smco410-z-wave-plus-smart-smoke-co-alarm-works-with-ring/
SMCO410 Z-Wave Plus Smart Smoke & CO Alarm | Home Assistant: https://community.home-assistant.io/t/first-alert-smoke-co-detector-new-zcombo-replacement-model-smco410-z-wave/431189
SMCO410 Z-Wave Plus Smart Smoke & CO Alarm | Amazon: https://www.amazon.com/dp/B0C7737373
SMCO410 Z-Wave Plus Smart Smoke & CO Alarm | Alibaba: N/A
ZEN55 DC Signal Sensor | Official: https://www.thesmartesthouse.com/products/zooz-z-wave-plus-smoke-and-co-detector-bridge-zen55-800lr
ZEN55 DC Signal Sensor | Home Assistant: https://www.support.getzooz.com/kb/article/1431-how-to-add-your-zen55-smoke-co-detector-bridge-to-home-assistant/
ZEN55 DC Signal Sensor | Amazon: https://www.amazon.com/dp/B0C9222222
ZEN55 DC Signal Sensor | Alibaba: N/A