Siemens RDG2..KN Room Thermostat

Introduction

The RDG2..KN series are room thermostats with KNX communications, enabling users to set ideal temperature, relative humidity, and CO2 levels (RDG204KN & RDG264KN). These thermostats offer operating modes including Comfort, Economy, and Protection. They can also operate in Auto mode based on a schedule via KNX bus or locally. The fan operates in either Auto mode or at a selected speed in Manual mode. Users can utilize factory settings or adjust them as needed.

Main Display and Controls

The main display area provides information and access to controls:

• Main display: Primary information area.
• Operating mode selection [*]: Selects the thermostat's operating mode.
• Scheduler [3]: Access to scheduling functions.
• Fan speed selection [4]: Adjusts fan speed.
• Escape button [5]: Cancels current operation or returns to previous menu.
• Delete schedule button [6]: Removes a selected schedule.
• Confirm parameters button [7]: Saves and confirms settings.
• Number of schedules or slave alarms indicator [13]: Shows active schedules or alarms.
• Outside temperature display [D]: Shows the current outside temperature.
• Parameter display [P]: Shows parameter numbers during configuration.
• Setpoint display digits [24.5]: Displays the target temperature.
• Time bar for schedule: Visual representation of scheduled times.
• Additional user information: Displays data like outside temperature, time of day (from KNX), relative humidity, or indoor air quality [18:32].
• Relative humidity indicator [%r.H]: Shows current relative humidity.
• Temperature unit indicator: Displays current temperature unit [°C / °F].
• CO2 values indicator: Shows CO2 concentration in ppm.
• Room temperature display: Shows the current room temperature [24.5 Value with thermometer].

Key control buttons and elements include:

• Operating mode button [*]: Activates operating mode selection.
• Fan mode button [B]: Controls fan operation.
• Rotary knob [C]: Used for adjusting values and navigating menus.
• Green leaf button [D]: Indicates energy-efficient settings.
• Protection hospitality mode or scheduler button [E]: Accesses specific modes or scheduler.

Status indicators include:

• Fresh air indication: [icon]
• Condensation in room (dewpoint sensor active) or humidity control active: [icon]
• Button lock: [icon]
• Automatic fan: [AUTO]
• Fan speed indicators: Fan speed I [? I], Fan speed II [? II], Fan speed III [? III].

Note: When P002 = 3, the icon [icon] is displayed, and the button can be used to switch units between °C and °F.

Operating Modes

The thermostat supports the following operating modes:

• Holiday mode [icon]
• Protection mode [icon]
• Economy mode [ECO]
• Comfort mode [icon]
• Cooling mode [icon]
• AUX Electric heater active [icon]
• Heating mode [icon]
• Scheduler mode [icon]
• Manual changeover [icon]
• Auto mode [AUTO]
• Temporary timer [icon]
• Fault [icon]

Changing Room Temperature

Turn the rotary knob [C] clockwise to increase, or counterclockwise to decrease the current room temperature setpoint. The adjustable range is 5...40 °C, which can be limited by parameters P013 and P016.

Adjusting Fan Speed

Press the right button repeatedly until the desired fan mode is reached.

• In Auto mode [AUTO], the fan speed is automatically selected by the thermostat based on the setpoint and current room temperature.
• In Manual mode, the fan operates independently at the speed set by the user: speed I, speed II, or speed III.

Changing Operating Mode

The operating mode can be changed using the operating mode button [*] or via external signals.

Comfort Mode

Maintains the room temperature at the setpoint, adjustable via the rotary knob.

Economy Mode

Maintains the room temperature at a lower or higher setpoint to save energy. It can be activated via the operating mode button (if P002 = 2) or external signals (e.g., keycard, presence detector). Factory setpoints are 15 °C for heating and 30 °C for cooling, adjustable via parameters P019 and P020.

Protection Mode

The thermostat stops operating. However, if the room temperature drops below 8 °C, heating is activated to protect the room against frost. This mode is also activated when a window contact (local or KNX) is triggered. Setpoints for Protection mode can be configured by an HVAC installer (e.g., Frost protection: [value] °C, Heating protection: [value] °C).

Auto Mode

Automatically switches between Comfort and Economy modes based on the KNX bus or local schedule (enabled via P005). If no schedule is available, Comfort mode is used. Important: If setpoints are set to Off, there is no protective heating or cooling function, posing a risk of frost.

Green Leaf Indication

The green leaf indicator signifies energy-efficient settings:

• Green leaf: Settings are within the preset energy-efficient range.
• Red leaf: Settings exceed the preset energy-efficient range. Users can press the red leaf button to return to the energy-efficient range.

Reminders and Faults

The thermostat may display reminders or fault messages:

• Filter Cleaning Reminder: "FIL **" message reminds you to clean the filter on your HVAC equipment.
• External Faults: Messages like "AL1 **", "AL2 **", "AL3 **" indicate external faults. These messages appear after a set number of "fan operating hours" and disappear when the thermostat is manually set to Protection mode. Specific fault codes (AL1, AL2, AL3) need to be configured by an HVAC installer.

Scheduler Function

The scheduler allows setting different operating modes and temperatures for specific times.

Setting a Schedule

1. Press the button [button] and then turn the rotary knob [C] or press button [button] continuously to select programming mode [PROG].
2. Press button [button] once to enter scheduler mode.
3. Turn the rotary knob [C] to select the weekday to be set, then press button [button] once.
4. Turn the rotary knob [C] to view existing schedules, then press button [button] once to select the schedule to edit.
5. The Comfort mode setting is displayed with icons [icon] and [icon]. Press button [button] once. The start time for Comfort flashes and can be changed by turning the rotary knob [C].
6. Press button [button] once to confirm the adjusted value and enter the Economy mode setting for the schedule. Icons [ECO] and [icon] are displayed. The start time for Economy flashes and can be changed by turning the rotary knob [C].
7. Press button [button] once to confirm the adjusted value. Users can then view other schedules by turning the rotary knob [C] and enter other schedule settings.

Note: Pressing the button [button] can delete any schedule, or pressing [Esc] cancels the change. A maximum of three schedules can be set per day.

Setting Time

Set the current time for the thermostat.

1. Press the button [button] and then turn the rotary knob [C] or press button [button] continuously to select programming mode [TIME].
2. Press button [button] once and then turn the rotary knob [C] to select the time format (12H or 24H).
3. If 12H format is selected, press button [button] once and then turn the rotary knob [C] to select AM or PM.
4. Press button [button] once to enter the hour setting. The hour value flashes and can be changed by turning the rotary knob [C].
5. Press button [button] once to confirm the adjusted value and enter the minutes setting. Repeat the steps for setting the minutes.

Note: When using 24-hour format, AMPM is not displayed.

Setting Date

Set the current date for the thermostat.

1. Press the button [button] and then turn the rotary knob [C] or press button [button] continuously to select programming mode [DATE].
2. Press button [button] once to enter date setting.
3. Turn the rotary knob [C] to select month, weekday, or year, then press button [button] once.
4. For example, to set the year: The Year value flashes and can be changed by turning the rotary knob [C].
5. Press button [button] to confirm the adjusted value, or [Esc] to cancel the change. Repeat steps for month and weekday settings.

Setting Away (Holiday Mode)

Configure the thermostat for periods when the building is unoccupied.

1. Press the button [button] and then turn the rotary knob [C] or press button [button] continuously to select programming mode [AWAY]. Holiday mode is displayed.
2. Press button [button] once to enter scheduler mode.
3. Turn the rotary knob [C] to adjust the holidays, then press button [button] once.
4. Set the start time (AWAY): Set the month [MON], then press button [button]. Set the day [DAY], then press button [button] once.
5. Press button [button] once to confirm the adjusted value. The idle page for Holiday mode is displayed once the start time is reached.

Button Lock

The button lock function prevents accidental changes.

• If the button lock function is enabled (parameter P028 = 2), pressing the right button [button] for 3 seconds locks or unlocks the buttons. Locked buttons are indicated by the key symbol [?].
• If "Auto lock" is configured (P028 = 1), the thermostat automatically locks the buttons 10 seconds after the last adjustment.

Commissioning (by qualified HVAC installer)

To adapt the thermostat to your system and optimize control performance, control parameters can be adjusted. This can be done during operation, either via the thermostat buttons or a commissioning tool.

Control Parameters

To change control parameters:

1. Press the left [←] and right [→] buttons simultaneously for 3 seconds, or until the device beeps (if buzzer function is enabled, P030).
2. Service Level: Release buttons and within 0.5-4 seconds, press the right button [→] again until "P001" is displayed.
3. Expert Level: Release buttons and within 0.5-4 seconds, press the left button [←] again until the temperature display disappears. Turn the rotary knob [C] counterclockwise at least 1.5 rotations. P050 will be displayed.
4. Select the required parameter by turning the rotary knob [C].
5. Press button [OK]. The current value of the selected parameter flashes and can be changed by turning the rotary knob [C].
6. Press button [OK] to confirm the adjusted value, or [Esc] to cancel the change.

Repeat steps 3-5 for additional parameters, or press [Esc] to quit parameter setting mode.

Note: If password protection is enabled, a password is required to enter parameter setting mode. Mistyping the password 5 times locks the thermostat for 5 minutes.

Symbols [?] and [icon] are displayed when locked.

Parameter List

Notes:

• *** When no time schedule via KNX exists, Auto equals Comfort.
• **** Parameter P027 is displayed only for application 2-pipe with electric heater.
• ***** These parameter values are valid for RDG204KN and RDG264KN.
• All temperature settings are in increments of 0.5 °C (except P006 of RDG204KN & RDG264KN is in 0.1 °C).