Turn it on
- 1It is always on (mains or AAA batteries). If the screen is blank, replace the 2 AAA batteries (RDD10.1).
Siemens RDD10 / RDD10.1 in English
An older beige Siemens room thermostat that just opens or closes the heating valve for its zone: one button toggles Comfort (sun) and Economy (moon), two set the temperature.
What does each button do?
- 1Hole / lamp · Small hole on the casing (likely the sensor vent). Not a button.
- 2Room temperature · Measured room temperature (22.5°C). Pressing +/- shows and flashes the setpoint instead.
- 3Comfort mode mark · ☀Sun = normal (comfort) setpoint active. Moon = energy-saving setpoint.
- 4Warmer · 🌡 +Press once to show the setpoint, again to raise it 0.5°C (5-35°C). Saves after 5 s.
- 5Colder · 🌡 −Lowers the setpoint by 0.5°C.
- 6Hourglass: auto-revert time · ⧗Sets how long a mode switch lasts before reverting (0.5-24 h). 00.0 = never reverts.
- 7Comfort / Economy · ☀/☾Switches between normal (sun) and energy-saving (moon) temperature.
What setting should I use?
Comfort ☀ 21-22°C, Economy ☾ 16-17°C at night or when out. Leave ⧗ at 00.0 unless you want automatic return.
How do I…?
Heat the room to a set temperature
- 1Make sure the sun ☀ shows (press ☀/☾ if you see the moon).
- 2Press 🌡+ once; the setpoint flashes.
- 3Press 🌡+ or 🌡− until it reads 22.0.
- 4Wait 5 seconds; it saves and shows the room temperature again.
Leave for a few days
- 1Press ☀/☾ so the moon ☾ shows.
- 2Set the moon setpoint about 16°C: with ☾ showing press 🌡− until 16.0.
- 3Press ☀/☾ again when you are back.
Run on a timer
- 1Press ⧗ once; the hours flash.
- 2Use 🌡+/− to pick 0.5-24 h.
- 3Now pressing ☀/☾ switches mode only for that long, then it reverts on its own. Set 00.0 to turn this off.
Turn it off
- 1Switch to ☾ and set its setpoint to 0°C, which means OFF. Only do this outside the cold season: there is a frost risk.
What do the words on the screen mean?
| ☀ | Comfort | Normal setpoint in use. |
|---|---|---|
| ☾ | Economy | Energy-saving setpoint in use (if economy is set to 0°C the controller is OFF). |
| 🔥 / heat symbol | Heating on | Valve open, zone heating. |
| 🌡 | Room temp shown | Number is the measured room temperature. |
| battery | Replace batteries | Battery model (RDD10.1): replace the 2 × AAA within two weeks. |
What trips people up on this model?
- The setpoint you edit belongs to whichever mode (sun or moon) is showing. Check the icon first.
- Economy at 0°C = no heating at all (frost risk).
- What the ☀/☾ button does with a timer depends on an installer DIP switch, so the auto-revert may go either direction.
Service line (Korean): Not printed on panel.