Homematic IP HMIP-SCTH230 smart home environmental sensor Wired

The Homematic IP HMIP-SCTH230 smart home environmental sensor Wired measures indoor CO2 concentration in ppm, ambient temperature and relative humidity. Designed for flush-mounted installation, the device requires both phase and neutral conductors and is powered from 230 V AC with a maximum switching capacity of 1150 W. A built-in relay output allows the sensor to directly control a connected consumer such as a lamp. Measured values and device status are accessible via the Homematic IP smartphone app. The compact 86 × 86 × 54 mm housing is compatible with common 55 mm frame systems and maintains the look of existing switch surfaces when integrated.

Advantages

The wired Homematic IP environmental sensor provides continuous, local monitoring of indoor air quality by reporting CO2, temperature and humidity. Its integrated five‑segment LED bar gives an immediate visual indication of CO2 load on the device itself, while the app offers historical and live values. The additional relay output enables combined use of one flush-mounted box for both air‑quality sensing and switched lighting or other loads. Screwless spring‑loaded terminals simplify wiring during installation, and the IP20-rated white housing fits standard installations without changing existing frame designs.

Suitable for

• Monitoring indoor air quality in living rooms, bedrooms and home offices
• Schools, meeting rooms and other spaces where CO2 levels affect comfort and performance
• Integration into existing 55 mm frame switch systems for combined sensing and lighting control
• Smart home setups using the Homematic IP app for remote monitoring and automation

Key specifications

• Measured parameters: CO2 concentration (ppm), temperature, relative humidity
• Power supply: 230 V AC (requires phase and neutral)
• Maximum switching capacity: 1150 W via built‑in relay output
• Connectivity: wired integration for Homematic IP systems with app visibility
• Housing dimensions: 86 × 86 × 54 mm; fits 55 mm frame systems
• Device colour: white; ingress protection: IP20

How to use

Install the sensor in a standard flush‑mounted box and connect phase and neutral to the screwless spring terminals. Mount the device at room height appropriate for accurate ambient readings, avoiding direct sunlight and sources of drafts or heat. After powering the device, pair or register it in the Homematic IP app to view live CO2, temperature and humidity readings, and configure thresholds or automation rules. Use the relay output to control a lamp or other consumer and link switching to CO2 thresholds, timers or manual controls within the Homematic IP system.

Recommendations

Position the sensor away from windows, HVAC outlets and direct heat sources to ensure representative air measurements. Use the LED indicator as a quick local guide to air quality and set app alarms or automation to ventilate or activate extraction when CO2 levels exceed recommended values. Verify secure wiring connections before restoring power and consult the Homematic IP compatibility list when integrating with existing 55 mm frame systems.