Heiman S1-TM: Matter Smoke Detector with Temperature and Humidity Sensors

The Heiman S1-TM is a Matter smoke detector that communicates via Matter over Thread. Its housing also contains temperature and humidity sensors. In addition to smoke, the detector therefore measures climate data that can be displayed in the connected smart home app.

Its features include a replaceable battery and a magnetic mount. Heiman lists Apple Home, SmartThings, Home Assistant and Homey as supported platforms.

Context: This article introduces the Heiman S1-TM using information from the manufacturer and product listings. I plan to integrate the detector into Home Assistant and show the setup and my experiences in a later article.

Heiman S1-TM: Technical specifications

Heiman offers several versions of the S1 series. The following overview refers to the S1-TM:

Feature	Specification
Wireless standard	Matter over Thread
Sensors	Smoke, temperature and humidity
Smoke detection	Optical detection using two wavelengths
Alarm sound	At least 85 dB at a distance of approximately three metres
Power supply	Replaceable CR123A lithium battery, 3 volts
Battery life	3.5 years according to the manufacturer’s table for the S1-TM; a conflicting product listing states up to five years
Sensor lifespan	Ten years according to the manufacturer
Dimensions	Approximately 70 mm in diameter and 37 mm high
Mounting	Magnetic mount or screws
Standard	EN 14604 according to the manufacturer

Matter over Thread: What you need for integration

To connect to your smart home, the Heiman S1-TM requires a Matter controller and a Thread Border Router. The controller integrates the detector into your smart home. The Border Router connects the Thread wireless network to your home network. First check which of these functions your existing devices already provide.

For Home Assistant, the Matter integration and Matter Server must be configured. With Home Assistant OS, the official Matter Server is installed when you set up the integration. An existing Home Assistant installation can be used; a new computer is not necessarily required. Examples of hardware for running Home Assistant include a Raspberry Pi*, Home Assistant Green* or Home Assistant Yellow*.

The Thread connection also requires a suitable Border Router. For example, a Home Assistant Connect ZBT-2* can be configured with Thread firmware and the OpenThread Border Router app. An existing compatible Thread Border Router can also be used. The wireless adapter alone is not a fully configured Border Router. The individual steps are described in the official Home Assistant Matter guide.

My article Set up IKEA MYGGBETT in Home Assistant shows the general pairing process for a Matter-over-Thread device. It explains the requirements and the steps in the Companion App, using the door and window sensor as an example. I will test the specific functions of the Heiman S1-TM separately.

Smoke detector with temperature and humidity measurement

In addition to smoke, the Heiman S1-TM measures temperature and humidity at its mounting location. These additional readings can provide an overview of the climate there without installing a separate climate sensor. A later hands-on test will show which readings and functions are available in Home Assistant and how the measurements perform in everyday use. My article about the IKEA TIMMERFLOTTE temperature and humidity sensor in Home Assistant already gives an insight into how such climate readings are displayed.

Optical smoke detection using two wavelengths

Heiman uses red and infrared light for smoke detection. The manufacturer calls this combination dual optics and describes it as a technology for distinguishing fire smoke from cooking fumes and water vapour.

The features also include a red alarm LED and a self-test button. According to the manufacturer, the detector provides audible and visual indications when it detects device faults.

The smoke inlets are arranged around the housing. Heiman describes the design as a 360-degree inlet. For fault monitoring, the manufacturer lists sensor errors and low battery voltage, among other things. I have not yet carried out my own measurements of response time or false alarm rates.

Replaceable battery and battery life

The manufacturer’s table for the S1 series specifies 3.5 years of battery life for the S1-TM. The five years listed there refer to the S1-M. By contrast, the product listing states up to five years for the S1-TM, so the figures are inconsistent. The CR123A battery is replaceable. According to the manufacturer, the detector provides audible and visual indications when battery voltage is low. The planned hands-on test will check whether and how a battery warning also appears in the relevant smart home app. The stated sensor lifespan of ten years is a separate specification.

Mounting with magnets or screws

The Heiman S1-TM is offered with a magnetic mount. Alternatively, it can be secured with screws. The magnetic mount allows you to remove the detector to change the battery, clean it or test it.

With a diameter of approximately seven centimetres and a height of 3.7 centimetres, the housing is compact.

Heiman S1-TM price and availability

On 27 September 2026, the limited-time promotional price for the Heiman S1-TM was €39.94. The stated recommended retail price was €46.99. The device was in stock at the time of the research. These figures represent a historical price snapshot. The price displayed by the product box appears below; the price and availability in the linked shop take precedence.

Product-box price as of 14 October 2026

Conclusion on the Heiman S1-TM?

The Heiman S1-TM is primarily a smoke detector that can be integrated into your smart home via Matter over Thread and can also measure temperature and humidity. Its replaceable battery and compact housing are practical features.

Are you already using smoke detectors with Matter over Thread? Let us know in the comments which models and Thread Border Router you use and how integration into your smart home works.

Source/photo: (Amazon / Heiman )