Siemens Smart Thermostat | RDS 120 | 2020 Review


Siemens RDS 120 Smart Thermostat – Overview

Siemens Smart Thermostat

Now there aren’t that many smart thermostats that we at RAVE about, but the new Siemens Wi-Fi Thermostat RDS 120 is definitely one of them.

The new RDS 120 smart thermostat from Siemens features some pretty cool functionalities for a thermostat. It’s sleek, black design also stands out – making it an attractive addition to your living room or bedroom.

In addition, the premium design and feel, is also a welcome change to the ‘plasticky’ design of other thermostats. It also basically boasts six powerful and accurate sensors, namely temperature, humidity, light, proximity, presence and organic particle detection.

The COOLEST part of this thermostat hands down would be it’s air quality and humidity monitoring function. This feature comes together with the thermostat itself. Home air quality is often overlooked by most home-owners in the US. Eeverything is often fine and dandy until a loved one comes down with a breathing / respiratory related issue. Health effects associated with indoor air pollutants include: Irritation of the eyes, nose, and throat, headaches, dizziness, and fatigue. More serious ones include respiratory diseases, heart disease, and cancer. (Source : Illinois Department of Public)

Siemens Wireless Thermostat Review

Siemens RDS 120 Smart Wireless Thermostat – Aesthetics

Now looks wise, the RDS 120 is definitely a winner. Featuring a sleek, black design that makes a fine addition to a modern or contemporary designed home. It features a bright and easy to read 3.5″ LCD display color display. The display has everything you need to know about your home temperature settings at a glance.

The actual dimensions of the display unit is featured below if you want to have a quick look. You can then plan on where you can mount it in your home, and if it could easily cover the area where your old thermostat is mounted currently.

Siemens Smart Thermostat
Actual dimension of the Siemens RDS 120 Smart Thermostat display unit

It’s nicely backlit display also means that key display data (current and set temperature) is available at a glance. This is thanks to a well-thought of touchscreen, that responds to the lighting conditions in the room and ensures optimal readability.

Siemens Smart Thermostat
The Green-Leaf display on the top right corner

The display screen also has a pretty neat One-touch Green Leaf to maximise energy efficient in your home. The Green Leaf button engages occupants in maximizing system efficiency. The Green Leaf will turn red if the scheduled setpoint is overridden. One touch will return the system to the programmed setpoint and the leaf will return to green.

Set point temperature changes can be made by sliding or tapping on the set point line to the left or right to change temperature, easy to read and control from display or phone app as well.

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Siemens RDS 120 Smart Wireless Thermostat – Installation

When it comes to installation, the RDS 120 from Siemens is also a breeze to install. This smart thermostat may be mounted directly on your home wall using drywall anchors and screws (included). For installation on a 2” x 4” conduit box, the use the appropriate mounting plate and plastic trim piece is required. These are also included with the box. The thermostat is also designed for maintenance-free operation.

An integrated navigation assistant facilitates commissioning, the entire process is complete within minutes in just a few steps.

The included installation guide is easy to read, and also has a colourful wire guide installation labelled for you to spot and install the wires. (See image below)

Siemens Smart Thermostat
The Siemens RDS120 includes a wire-guide installation for easy installation
The Siemens RDS 120 system compatibility table

This smart thermostat is designed to control Heat Pump or Conventional HVAC heating and cooling applications. It can control up to three stages of heating,and two stages of cooling in conventional systems. In heat-pump based system, it can control up to two compressors, and two stages of auxiliary heat.

The thermostat consists of the following parts:

  • Front housing with touch screen and sensors
  • Back housing with terminals and relays
  • Mounting hardware for installation on 2’’×4’’ electrical box or directly on drywall
Siemens Smart Thermostat Review

Siemens RDS 120 Smart Wireless Thermostat – Features

Now moving onto the functionalities and features offered by this thermostat. The thermostat is integrated with sensors for room temperature, air quality, humidity and the presence of occupants can be combined with external sensors for outside temperatures or switches for opening windows.

The touch screen displays the essential information for an easy operation at home. A Green Leaf symbol (on the thermostat display) indicates whether the heating equipment is running at top energy efficiency. A precence sensor that thermostat is equipped with automatically switches on, ensuring the optimal comfort of occupants in the room.

Siemens RDS 120 Smart Wireless Thermostat Video

The weekly time program for heating and domestic hot water are visible on the mobile app and just as easily adjustable as well. Also, as the engineers at Siemens have worked hard to load numerous control functions via the app and touchscreen; that the intuitive operation and sensor-based monitoring of room air quality, the RDS 120 thermostat is able to create perfect places based on the requirements of individual room users.

Thermostat control is intuitive using the mobile app or the local touchscreen. The smart thermostat is also able to connect to a WLAN compatible router that ensures data is transferred to the Siemens cloud. Users can access this data from the app and conveniently control up to 12 thermostats from their mobile phones. The app is available in a number of languages, including German, English, French, Italian, Spanish and Chinese.

The smart thermostat has a self-learning algorithm, that determines the best heating strategy for achieving the desired comfort level with maximum energy-efficiency. This ensures that the thermostat selects the optimal heating start time depending on the sensor readings. Within a day, the thermostat adjusts the heating strategy to the room and the heating devices in use, thus contributing significantly to lower energy consumption and reduced energy costs.

The screen and its diverse information and control options can also be password protected to keep the kids from playing around with them.

Siemens Smart Thermostat Review

Key features of the Siemens RDS 120 Smart Wireless Thermostat:

  • Intuitive display and user interface – Changing the temperature is a breeze by sliding or tapping on the set point line to the left or right to change temperature – easy to read and control from display screen or your phone app.
  • Air Quality Sensing – the LCD display will show Good, Okay or Poor air quality to inform you of the indoor air quality in your home
  • Mobile device application – Thermostat interaction via mobile device – allows ability to connect to and control your thermostat from anywhere via your Smartphone app.
  • Wi-Fi – Wi-Fi connectivity to enable mobile access – access from mobile devices from any location in the world!
  • Software Updates – Firmware updates to the RDS120 smart thermostat and the mobile device application will occur automatically with no user interaction and will not affect current settings.
  • Scheduling – you can set up daily schedules with 3 different operating modes (comfort, economy and unoccupied) – utilizing a programmed schedule can provide more efficient control based on occupancy to improve energy savings.
  • Optimized Energy Efficiency – 6 internal sensors (temperature, humidity, light, proximity, occupancy and VOC) allows the device to provide energy-efficient operations to its controls and monitoring.
  • Energy consumption monitoring – the mobile app displays running hours (past 7 days, last 4 weeks and last 12 months) for heating and cooling operation). This gives you the ability to understand running hours to make more energy efficient decisions and achieve further energy bill savings.
  • Advanced Settings – Temperature setting limitations (for use in public spaces), Screen lock protection (limits unauthorized access), Temperature sensing options (optional inputs for remote temperature sensing or averaging of two sensors.

Siemens RDS 120 Smart Wireless Thermostat – Summary

In summary, the Siemens RDS 120 Smart Wireless Thermostat is packed with features that ensures that your home’s temperature is maintained optimally at all times. It’s Green Leaf feature and optimal energy efficiency will also result in energy and heating bill savings in no time for your home.

The standout feature of the air quality monitoring gives you an idea of when to change your HVAC filters and do the necessary servicing – something we often take for granted.

We also love it’s premium look and feel of the thermostat display unit. It’s wireless connectivity and app pairing and use is also seamless and we had no problems with it during our 2 week trial with the unit.

Premium look & feel. Love the LCD display.Priced at over $200
Programmable setting for 7 days
Home humidity and air quality sensors built-in
Does not require a C-Wire for installation
Smart Thermostat Review
Review Date
Reviewed Item
Siemens RDS 120 Smart Wireless Thermostat | 2020 Review
Author Rating
Product Name
Siemens RDS 120 Smart Thermostat
USD 246
Product Availability
Available in Stock

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