Thermoflow OT 5 Combi Under-Sink Water Heater

1. Important Safety Instructions

Please read these instructions carefully before installation and operation. Failure to follow these instructions may result in property damage, personal injury, or death. Keep this manual for future reference.

• Electrical Safety: This appliance must be installed by a qualified electrician in accordance with local and national electrical codes. Ensure the power supply matches the appliance's rating. Do not operate with a damaged power cord or plug.
• Water Safety: Installation must be performed by a qualified plumber. This is a low-pressure water heater and must only be connected to a low-pressure faucet. Connecting to a high-pressure system will cause damage and potential leaks.
• Children and Vulnerable Persons: This appliance can be used by children aged 8 years and above and persons with reduced physical, sensory or mental capabilities or lack of experience and knowledge if they have been given supervision or instruction concerning use of the appliance in a safe way and understand the hazards involved. Children shall not play with the appliance. Cleaning and user maintenance shall not be made by children without supervision.
• Temperature: Hot water can cause severe burns. Exercise caution when adjusting the temperature and using hot water.
• Maintenance: Only qualified personnel should perform repairs or maintenance beyond basic cleaning.

Always refer to the manual and use appropriate tools for installation and maintenance.

2. Product Overview

The Thermoflow OT 5 Combi is a compact 5-liter electric under-sink water heater designed to provide hot water efficiently for kitchens or bathrooms. It features an energy-saving mode and is rated for energy efficiency class A. This model includes a low-pressure faucet with dual handles for convenient operation.

Front view of the Thermoflow OT 5 Combi water heater with the included low-pressure faucet.

The main water heater unit, showing the temperature control knob and indicator light.

3. Package Contents

Please check that all components are present in the package:

• Thermoflow OT 5 Combi Under-Sink Water Heater Unit
• Low-Pressure Faucet with Dual Handles
• Mounting Materials (screws, anchors)
• Instruction Manual

Included mounting hardware: screws and wall anchors.

4. Installation Instructions

Installation should only be carried out by qualified professionals (electrician and plumber) to ensure safety and proper function.

4.1 Pre-Installation Checks

• Ensure the installation location is suitable for wall mounting and can support the weight of the unit when full (approx. 7.8 kg).
• Verify that the electrical supply matches the unit's requirements (230V).
• Confirm that you have a low-pressure water supply and a compatible low-pressure faucet.

4.2 Mounting the Unit

The water heater is designed for wall mounting, typically under a sink. Its compact dimensions (42 cm H x 27 cm W x 18 cm D) allow for space-saving installation.

1. Mark the drilling points on the wall according to the unit's mounting brackets.
2. Drill holes and insert the provided wall anchors.
3. Secure the mounting screws, leaving enough space to hang the unit.
4. Carefully hang the water heater unit onto the secured screws.

Example of the Thermoflow OT 5 Combi installed under a sink.

4.3 Water Connection

Connect the water heater using G 1/2-inch connections. Ensure all connections are watertight and that the low-pressure faucet is correctly installed.

• Connect the cold water inlet to the designated port on the water heater.
• Connect the hot water outlet from the water heater to the hot water inlet of the low-pressure faucet.
• Important: This unit requires a low-pressure faucet. Do not use a standard high-pressure faucet.

Close-up view of the included low-pressure faucet.

4.4 Electrical Connection

Plug the appliance into a properly grounded 230V electrical outlet. Ensure the outlet is easily accessible.

4.5 Initial Filling

Before switching on the power, open the hot water tap on the faucet and allow water to flow until it runs smoothly and all air is expelled from the tank. Close the hot water tap once the tank is full.

5. Operating Instructions

Once installed and filled, the Thermoflow OT 5 Combi is ready for operation.

5.1 Temperature Adjustment

The unit features a rotary knob on the front for temperature adjustment. The temperature range is approximately 35°C to 75°C.

• Turn the knob clockwise to increase the temperature.
• Turn the knob counter-clockwise to decrease the temperature.
• The indicator light will illuminate when the unit is actively heating water.

5.2 Energy-Saving Mode

The unit includes an energy-saving mode (often marked 'E' or similar on the dial) to optimize energy consumption while still providing comfortably warm water.

5.3 Water Heating

The 5-liter tank can heat water from 10°C to 65°C in approximately 10 minutes, providing quick access to hot water.

6. Maintenance

Regular maintenance ensures the longevity and efficient operation of your water heater.

6.1 Cleaning

• Disconnect the power supply before cleaning.
• Wipe the exterior of the unit with a soft, damp cloth. Do not use abrasive cleaners or solvents.
• Clean the faucet regularly to prevent limescale buildup.

6.2 Descaling

Depending on your water hardness, limescale can build up inside the tank and on the heating element, reducing efficiency. Descaling should be performed periodically by a qualified technician.

6.3 Regular Checks

Periodically inspect the unit for any signs of leaks, damage to the power cord, or unusual noises. If any issues are detected, disconnect power and contact a qualified technician.

7. Troubleshooting

This section addresses common issues you might encounter. For problems not listed here, or if solutions do not resolve the issue, contact a qualified service technician.

7.1 No Hot Water

• Check Power: Ensure the unit is plugged in and the power outlet is functioning. Check your circuit breaker.
• Temperature Setting: Verify the temperature knob is set to a desired heating level, not 'off' or 'E' if maximum heat is desired.
• Indicator Light: If the indicator light is not on, the unit may not be heating.

7.2 Water Not Hot Enough

• Temperature Setting: Adjust the temperature knob to a higher setting.
• Tank Capacity: Remember this is a 5-liter unit. Continuous use may deplete the hot water supply quickly. Allow time for reheating.
• Limescale Buildup: Significant limescale can reduce heating efficiency. Professional descaling may be required.

7.3 Leaks

• Connection Points: Check all water connections for tightness. Ensure they are properly sealed.
• Low-Pressure System: Critical Warning: Ensure the unit is connected to a low-pressure faucet and system. Connecting to a high-pressure system will cause leaks and damage the unit. If you suspect this is the case, immediately disconnect the water supply and power, and contact a plumber.
• Internal Leak: If leaks persist after checking connections, an internal component may be damaged. Disconnect power and water, then contact service.

8. Technical Specifications

Below are the technical specifications for the Thermoflow OT 5 Combi water heater:

Technical drawing showing the dimensions of the water heater unit.

9. Warranty and Support

For information regarding the product warranty, please refer to the documentation provided with your purchase or visit the official Thermoflow website. For technical support, service, or spare parts, please contact your retailer or the manufacturer's customer service department.