Siemens designs this thermostat with exceptional performance. The RDJ 100 FR / SET is excellently suited for moving around the house without electrical cables. This radio wave thermostat allows you to bypass the installation constraints of thermostat cables and is especially suitable for those who are not working and want a product that is simple and immediate to use.

The Siemens RDJ 100 FR / SET thermostat operates on batteries and can be placed anywhere in the house as long as it is away from heat sources.

Adjustments and Display

Siemens RDJ 100 FR / SET thermostat display

Button Functions

The wheel allows you to quickly change the temperature and override the one set for the current operation; however, the temperature will reset at the next operation. When you adjust the temperature using the wheel, the hand symbol appears, indicating that it is operating in manual mode.

On the Siemens RDJ 100 FR / SET thermostat, we have several buttons and selectors.

The right selector is primarily used for adjustments:

  • Current time adjustment
  • First Event A1 adjustment
  • Second Event A2 adjustment
  • Third Event A3 adjustment
  • Fourth Event A4 adjustment
  • Comfort Temperature adjustment (T Sun)
  • Economy Temperature adjustment (T Moon)
  • RUN Mode (ALWAYS set back to RUN mode to start heating)

The left selector, on the other hand, allows us to choose between:

  • AUTO Operation (Automatic): the thermostat follows the set programming
  • Permanent Comfort Operation: The thermostat uses the comfort temperature for all hours of the day
  • Permanent Economy Operation: The thermostat uses the economy temperature for all hours of the day
  • Off Operation: The thermostat goes into frost protection mode.

Set the Correct Time

Setting the time on the RDJ 100 FR/SET thermostat is very straightforward.

  • Use the right selector in the clock position (all the way up) and use the wheel to adjust to the correct time.
  • Make sure to set the time in accordance with the Daylight Saving changes.
  • Once finished, always set the selector back to the RUN position

Frequently Asked Questions

Here are some frequently asked questions about this product:

How exactly does the "AUTO Operation (Automatic)" function work on the Siemens RDJ 100 FR/SET thermostat?

You have 4 events. When the thermostat is set to automatic mode, it follows the set times. Here's an example of programming:

  • A1 turns on (6:00 in the morning)
  • A2 turns off (8:00 in the morning)
  • A3 turns on (5:30 in the evening)
  • A4 turns off (10:00 in the evening)

The thermostat switches between the two Comfort and Economy temperatures automatically.

What is the difference between the "Comfort Temperature adjustment (T Sun)" and the "Economy Temperature adjustment (T Moon)"?

You can interpret the two temperatures in this way:

  • Sun Temperature: To be used when the apartment is occupied, so during the day. You can think of it as the 'on' temperature.
  • Moon Temperature: To be understood as the 'off' temperature, you can certainly use it during the night and during a specific time frame in the day.

How can I ensure that my set temperature is not overridden during the next event?

If you use the manual function for extended periods, we suggest you set the left selector to the Permanent Comfort position.

How do I know when it's time to replace the thermostat batteries?

A low battery symbol appears on the display, alerting you it's time for a change. The device will, however, still function for a short while.

Can I use rechargeable batteries for the RDJ 100 FR/SET thermostat?

We strongly advise against using them, as the thermostat communicates via radio waves with the receiver and requires a good charge that rechargeable batteries might not provide.

How does the RDJ 100 FR/SET thermostat handle frost protection mode?

If the thermostat is set to OFF (from the left selector), it's not completely turned off. If the room temperature drops to 8 degrees Celsius, the thermostat will heat the environment to prevent freezing.

What are the benefits of using the WIFI RDJ 100 FR/SET Thermostat compared to other traditional thermostats?

  • The thermostat caters to the needs of older individuals who typically want a quick heating adjustment.
  • The central knob assists with this.
  • This model also allows connection where no boiler connection is prearranged.
  • There's no need to drill any holes to install the thermostat.
  • The thermostat meets all modern accounting requirements.


Are there any precautions to take during installation to ensure the device isn't exposed to humidity or water?

Yes, special care should be given to the receiver connected to the boiler. Ensure that:

  • It isn't installed near sinks or water sources.
  • It isn't positioned beneath the boiler (there's always a possibility that the boiler might leak water in the future).

Remember, the receiver is connected to the high-voltage network

Useful Tips

Here are some useful tips for using your WIFI RDJ 100 FR / SET Thermostat:

  • Always remember to set the operation selector (the one on the right) to RUN for the correct heating use.
  • Be cautious when using Permanent Comfort for extended periods, as it could become costly in terms of consumption.

Battery Replacement:

Always check the battery charge; this thermostat operates using radio waves, so we suggest replacing the batteries at least once a year.

  • Use only high-quality disposable batteries.
  • Rechargeable batteries have low amperage and could cause issues with heating continuity.

Mounting and Installation

We always recommend consulting a specialized technician for the installation of the Siemens RDJ 100 FR / SET thermostat. This is because the receiver needs to be connected to the boiler both for the thermostat contact and for the electrical power from the grid.

The technician will use the Normally Open and Common contacts to activate the heating and will position the receiver in a location outside the boiler to ensure the device is not at risk of getting wet in the event of a leak

Technical Specifications

Feature Details
Product Name Wireless room thermostat with 24-hour timer and LCD RDJ100RF/SET
Programmability For heating systems
Operating Modes Automatic, Comfort, Energy Saving, Frost Protection
Time Intervals 24-hour timer switch
Service Interval Reminder Yes
Display Large size LCD
Temperature Limitations Minimum and maximum setting
Transmitter RDJ100RF, battery powered
Receiver RCR100/433, grid powered
Usage Control of ambient temperature in heating systems
Typical Applications Homes, residential buildings, schools, offices
Compatible Equipment Thermal or zone valves, combined boilers, gas or oil burners, pumps
Temperature Control RDJ100RF/SET offers temperature control both in 2-position and with PID learning
Control Algorithm 2-position or PID
Control Mode (P01) Default setting: "PID slow"
Temperature 0…+40 °C
Humidity <90% r.h.
Power Supply DC 3 V (2 x 1.5 V alkaline AA batteries)
Battery Life >1 year (with AA alkaline batteries)
Radio Frequency ISM 433 MHZ band
Maximum Radio Power 4.19 dBm
Setting Range 5…30 °C
Default Comfort Setting 20 °C
Default Energy Saving Mode 10 °C
Protection IP20
Weight 475 g (RDJ100RF/SET including packaging)
Front Color Signal white RAL9003
Case Material ABS

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