AEG BOI 5 U Under-Sink Low-Pressure Water Heater Instruction Manual

1. Product Overview

The AEG BOI 5 U is a compact, 5-liter under-sink water heater designed for single tap point supply, typically in kitchens or bathrooms. It operates as an open (vented) small storage unit, providing hot water with continuous temperature selection.

• Storage Volume: 5 liters
• Temperature Range: Approximately 35°C to 85°C, continuously selectable.
• Installation: Designed for under-sink, wall-mounted installation.
• Energy Efficiency: Class A, thanks to high-quality thermal insulation.
• Safety Features: Adjustable temperature limit for scald protection and a resettable safety temperature limiter.

This unit is ready to plug in, requiring only a standard socket and a cold water connection.

Front view of the AEG BOI 5 U water heater, showing the temperature control dial and power plug.

2. Important Safety Information

Please read all safety instructions carefully before installation and operation to prevent injury or damage.

• Low-Pressure Fittings Only: This appliance MUST only be used with low-pressure (pressure-free) fittings. These fittings are identifiable by having three connection hoses. Do NOT use with standard pressurized fittings or hose shower fittings, as this can cause severe damage to the unit and potential leaks.
• Electrical Safety: Ensure the power supply is disconnected before any installation, maintenance, or repair work. The unit operates on 230 Volts.
• Initial Startup: Always ensure the water heater is completely filled with water BEFORE connecting it to the electrical supply and switching it on. Operating the unit dry will damage the heating elements.
• Temperature Limit: The adjustable temperature limit provides child safety and scald protection. Set the temperature appropriately to avoid burns.
• Qualified Personnel: Installation and complex maintenance should be performed by a qualified professional.
• Resetting Safety Limiter: If the safety temperature limiter activates, it can be reset by pulling the power plug from the socket.

3. Package Contents

Verify that all components are present in the package:

• AEG BOI 5 U Small Storage Water Heater
• Operating and Installation Instructions (this manual)
• Wall Hanging Bracket

The AEG BOI 5 U water heater along with its included documentation and energy label.

4. Setup and Installation

The AEG BOI 5 U is designed for under-sink, wall-mounted installation. Ensure you have a suitable location with access to a cold water supply and a standard electrical socket.

4.1 Pre-Installation Checks

• Confirm you have a low-pressure faucet with three connection hoses.
• Ensure the installation area is protected from frost.
• Verify the electrical supply matches the unit's requirements (230 Volts).

4.2 Mounting the Unit

1. Select a suitable wall location under the sink, ensuring enough space for connections and future access.
2. Use the provided wall hanging bracket to mark drilling points.
3. Drill holes and securely fasten the bracket to the wall.
4. Hang the water heater onto the bracket.

Rear view of the water heater, illustrating the wall mounting points.

4.3 Water Connections

CRITICAL: Only connect to a low-pressure faucet.

1. Connect the cold water supply to the designated inlet on the water heater (usually marked blue or with an arrow pointing in).
2. Connect the hot water outlet from the water heater (usually marked red or with an arrow pointing out) to the hot water inlet of your low-pressure faucet.
3. Connect the third hose from the low-pressure faucet to the cold water supply.
4. Open the cold water supply valve and turn on the hot water tap on your faucet to allow the unit to fill with water. Let water run until it flows smoothly, indicating the unit is full and air has been purged.

Installation diagram illustrating connections to a low-pressure faucet. Note the critical requirement for a low-pressure fitting.

4.4 Electrical Connection

1. IMPORTANT: Ensure the water heater is completely filled with water before plugging it in.
2. Plug the power cord into a standard, properly grounded electrical socket.

Example of the AEG BOI 5 U installed discreetly under a kitchen sink.

5. Operating Instructions

5.1 Temperature Selection

The temperature of the water can be continuously selected using the rotary dial on the front of the unit, ranging from approximately 35°C to 85°C. Turn the dial clockwise to increase the temperature and counter-clockwise to decrease it.

5.2 Adjustable Temperature Limit (Scald Protection)

The unit features an adjustable temperature limit to prevent accidental scalding, especially important in households with children. Consult the detailed instructions in the full manual for how to set this limit, typically by adjusting a mechanism behind the main dial.

5.3 Normal Operation

Once installed and powered, the unit will heat the water to the selected temperature. The indicator light on the front will illuminate when the heating element is active and turn off once the set temperature is reached. The unit will automatically reheat water as it is used or as the temperature drops.

6. Maintenance

Regular maintenance ensures optimal performance and longevity of your water heater.

• Cleaning: Clean the exterior of the unit with a damp cloth. Do not use abrasive cleaners or solvents.
• Descaling: In areas with hard water, limescale can build up over time. Descaling should be performed by a qualified technician to avoid damaging internal components. The frequency depends on water hardness and usage.
• Inspection: Periodically check for any signs of leaks around the connections. Address any leaks immediately.
• Winterization: If the unit is in an area prone to freezing and will not be used for an extended period, it should be drained to prevent damage from freezing water. Consult a professional for proper draining procedures.

Always disconnect the power supply before performing any maintenance.

7. Troubleshooting

If you encounter issues with your AEG BOI 5 U water heater, refer to the following common troubleshooting steps:

• No Hot Water:
  • Check if the unit is plugged in and the power outlet is functional.
  • Verify the temperature dial is set to a desired temperature.
  • If the safety temperature limiter has tripped, unplug the unit for a few minutes, then plug it back in to reset.
  • Ensure the cold water supply is open and the unit is filled with water.
• Water Not Hot Enough:
  • Increase the temperature setting on the dial.
  • Ensure the hot water tap is not mixing with cold water (common with single-lever faucets).
• Leaks:
  • Immediately turn off the water supply and disconnect power.
  • Check all water connections for tightness.
  • Confirm that a low-pressure faucet is correctly installed. Using a high-pressure faucet will cause leaks and damage.
  • If leaks persist, contact a qualified plumber.
• Unit Not Heating (Indicator Light Off):
  • Check power supply and circuit breaker.
  • Reset the safety temperature limiter by unplugging and replugging the unit.

For issues not resolved by these steps, contact AEG customer support or a qualified service technician.

8. Specifications

Dimensional drawing of the AEG BOI 5 U water heater.

Energy efficiency label for the AEG BOI 5 U.

9. Warranty and Support

For warranty information, please refer to the documentation provided at the time of purchase or visit the official AEG website. Warranty terms and conditions may vary by region and retailer.

For technical support, spare parts, or service inquiries, please contact AEG customer service. Contact details can typically be found on the manufacturer's official website or in your purchase documentation.

When contacting support, please have your model number (BOI 5 U) and serial number (if applicable) ready.