Jung AUT238DWW Programmable Thermostat LCD Display Cover User Manual

1. Introduction

The Jung AUT238DWW is an LCD display cover designed for the Jung UT 238 E programmable thermostat mechanism. This unit provides a user interface for precise control over your heating system, featuring a clear display and intuitive buttons for programming and adjustments. It integrates a weekly timer to manage heating schedules efficiently, ensuring comfort and energy savings.

Key features include:

• Three adjustable temperature settings: Comfort, Setback (night/economy), and Frost Protection.
• Automatic summer/winter time switching.
• Temperature detection via internal and/or external sensor.
• Additional energy-saving button for reduced temperature mode.
• "Party" mode to extend comfort temperature for selected periods.
• Power reserve for settings retention during power outages.
• Cooling function for passive cooling systems.

2. Safety Instructions

Please read these instructions carefully before installation and operation. Keep this manual for future reference.

• Installation should only be performed by a qualified electrician in accordance with local regulations.
• Ensure the power supply is disconnected before any installation or maintenance work.
• Do not expose the device to moisture, extreme temperatures, or direct sunlight.
• Do not open or attempt to repair the device yourself. Refer all servicing to qualified personnel.

3. Product Components and Overview

The Jung AUT238DWW display cover consists of an LCD screen and several control buttons. Refer to the image below for a visual guide to the main components.

Key Controls:

• LCD Display: Shows current temperature, time, day of the week, and active mode icons.
• '+' and '-' Buttons: Used to adjust values such as time or temperature.
• SET Button: Confirms set values. If not pressed within 1 minute after adjustment, the display returns to normal mode without saving changes.
• PROG Button: Allows access to programming functions and returns to the normal time program.
• Star/Snowflake Button: (Left button) Likely for quick access to Comfort or Frost Protection modes.
• Moon Button: (Right button) Likely for quick access to Setback (night) mode.

4. Installation and Initial Setup

This AUT238DWW unit is a display cover designed to be mounted onto the Jung UT 238 E programmable thermostat mechanism. Ensure the UT 238 E mechanism is correctly installed and wired according to its specific instructions before attaching this display cover.

4.1 Attaching the Display Cover

1. Ensure the power supply to the thermostat mechanism is completely disconnected at the main circuit breaker.
2. Carefully align the AUT238DWW display cover with the UT 238 E thermostat mechanism.
3. Gently press the cover into place until it clicks securely. Do not force it.
4. Restore power to the thermostat mechanism. The display should illuminate.

4.2 Initial Time and Date Setting

Upon first power-up or after a prolonged power outage (beyond the power reserve), you may need to set the current time and date. Refer to the "Operating Instructions" section for detailed steps on using the +, -, and SET buttons to adjust these values.

5. Operating Instructions

5.1 Basic Operation

To adjust values such as time or temperature, use the + or - buttons. Confirm your settings by pressing the SET button. If the SET button is not pressed within 1 minute after the last button press, the display will automatically revert to the normal display mode, and any unsaved changes will be lost.

Pressing the PROG button allows you to navigate through programming menus or return to the normal time program.

5.2 Understanding Thermostat Modes

The thermostat operates by controlling the heating system based on three adjustable temperature settings at specific times:

• Comfort Temperature: Typically used during the day or periods of presence.
• Setback Temperature (Economy/Night): Usually applied during the night or periods of absence to save energy.
• Frost Protection Temperature: Used during extended periods of absence (e.g., holidays) to prevent the heating system from freezing. This temperature is set just high enough to protect the system.

5.3 Weekly Timer Programming

The integrated weekly timer allows for time-controlled temperature management for a single room or floor heating. You can set up to 32 individual switching times throughout the week. For each switching time, you define the start time, end time, and the desired temperature mode (Comfort, Setback, or Frost Protection).

1. Press the PROG button to enter the programming menu.
2. Use the + or - buttons to navigate through the program slots (e.g., P1, P2, etc.).
3. Press SET to select a program slot.
4. Use + or - to set the start time, then press SET.
5. Use + or - to set the end time, then press SET.
6. Use + or - to select the desired temperature mode (Comfort, Setback, Frost Protection) for this period, then press SET.
7. Repeat for all desired switching times. Press PROG to exit the programming menu.

The system includes heating optimization, which means it will activate heating in advance to ensure the desired temperature is reached precisely at the programmed time.

5.4 Special Functions

• Energy Saving Button: An additional button allows for quick switching to the reduced (setback) temperature.
• "Party" Mode: Activates the comfort temperature for a selectable period of 1 to 4 hours, overriding the current program. This is useful for temporary extensions of comfort.
• Cooling Function: The thermostat supports a simple cooling function for passive cooling systems (e.g., via geothermal exchangers). Refer to the UT 238 E mechanism manual for activation details.

6. Maintenance and Care

The Jung AUT238DWW display cover requires minimal maintenance.

• Cleaning: Wipe the display and buttons with a soft, dry, or slightly damp cloth. Do not use abrasive cleaners, solvents, or chemical sprays, as these can damage the surface.
• Battery (Power Reserve): The device features a power reserve (capacitor, not a battery) that retains settings for up to 4 hours during power interruptions and programming for up to 10 years. No user maintenance is required for this feature.

7. Troubleshooting

If you encounter issues with your Jung AUT238DWW display cover or the connected thermostat mechanism, consider the following:

• Display is blank: Check the power supply to the thermostat mechanism. Ensure it is correctly installed and receiving power.
• Settings not saving: Ensure you press the SET button to confirm changes after adjusting values. If you wait too long (over 1 minute), changes will not be saved.
• Incorrect temperature readings: Verify that the temperature sensor (internal or external, depending on configuration) is not obstructed and is functioning correctly.
• Heating not responding: Check the programming schedule to ensure the thermostat is set to a heating mode and desired temperature. Verify the UT 238 E mechanism is correctly wired to your heating system.

For persistent issues, consult the full manual for the Jung UT 238 E thermostat mechanism or contact Jung customer support.

8. Technical Specifications

9. Warranty and Support

9.1 Warranty Information

Specific warranty details for the Jung AUT238DWW are typically provided with the product packaging or can be found on the official Jung website. Please retain your proof of purchase for warranty claims.

9.2 Customer Support

For technical assistance, troubleshooting, or further information regarding your Jung AUT238DWW display cover or the UT 238 E thermostat mechanism, please contact Jung customer support through their official website or the contact details provided in your product documentation.

You can typically find support information on the Jung official website.