1. Introduction
This manual provides essential information for the safe and efficient installation, operation, and maintenance of your Thermex H HIT 15-U Pro Under-Sink Water Heater. Please read these instructions carefully before installation and use, and keep them for future reference.
The Thermex H HIT 15-U Pro is a compact, wall-mounted electric water heater designed for under-sink installation, providing hot water efficiently for domestic use. It features a modern design and includes an inlet combination for safety.
2. Safety Information
WARNING: Failure to follow these safety instructions could result in electric shock, fire, property damage, or personal injury.
- Ensure the power supply matches the specifications of the water heater (230V, 1500W).
- Installation must be performed by a qualified professional in accordance with local regulations and standards.
- Do not operate the water heater if it is damaged or malfunctioning.
- Always disconnect the power supply before performing any maintenance or repairs.
- The unit must be properly grounded.
- Do not block the pressure relief valve or any other safety devices.
- This appliance is not intended for use by persons (including children) with reduced physical, sensory or mental capabilities, or lack of experience and knowledge, unless they have been given supervision or instruction concerning use of the appliance by a person responsible for their safety.
3. Package Contents
Verify that all components are present before beginning installation:
- Thermex H HIT 15-U Pro Water Heater Unit
- Inlet Combination (Pressure Limiter and Non-Return Valve)
- Mounting Bracket and Fasteners (screws, wall plugs)
- Connection Cable with Plug
- User Manual (this document)
Figure 3.1: Included components, showing the inlet combination valve, mounting bracket, screws, and wall plugs necessary for installation.
4. Setup and Installation
The Thermex H HIT 15-U Pro is designed for wall-mounted installation, typically under a sink, with connections facing upwards. Ensure adequate space for maintenance and ventilation.
4.1 Mounting the Unit
- Choose a suitable wall location under the sink that can support the weight of the water heater when full (approx. 9 kg empty + 15 kg water = 24 kg).
- Mark the drilling points for the mounting bracket on the wall.
- Drill holes and insert wall plugs. Secure the mounting bracket firmly to the wall using the provided screws.
- Carefully hang the water heater unit onto the mounting bracket. Ensure it is securely seated.
Figure 4.1: Rear view of the Thermex H HIT 15-U Pro water heater, illustrating the integrated mounting points designed to hook onto the wall bracket.
4.2 Water Connections
The unit features 1/2 inch connections. The inlet combination (pressure limiter and non-return valve) must be installed on the cold water inlet.
- Connect the cold water supply to the blue-marked inlet pipe of the water heater. Install the included inlet combination valve here.
- Connect the hot water outlet to the red-marked outlet pipe of the water heater.
- Ensure all connections are tight to prevent leaks. Use appropriate sealing materials if necessary.
- Open the cold water supply valve and allow the tank to fill completely. Open a hot water tap in your sink to release air from the system until water flows steadily.
Figure 4.2: Close-up view of the water heater's underside, showing the blue-colored cold water inlet and red-colored hot water outlet connections. The inlet combination valve should be attached to the blue inlet.
4.3 Electrical Connection
- Ensure the water heater is filled with water before connecting to power.
- Plug the connection cable into a grounded 230V electrical outlet.
5. Operating Instructions
Once installed and connected, the Thermex H HIT 15-U Pro is ready for operation.
5.1 Control Panel
Figure 5.1: The central control knob allows adjustment of the water temperature. The 'Power' indicator light illuminates when the unit is powered, and the 'Heating' light indicates active heating.
- Temperature Control Knob: Located centrally, this knob allows you to set the desired water temperature. Turn it clockwise to increase the temperature. Settings typically include 'Min', 'Eco', and 'Max'. The 'Eco' setting is recommended for energy efficiency.
- Power Indicator Light: (Labeled 'Power') This light illuminates when the water heater is connected to the power supply and switched on.
- Heating Indicator Light: (Labeled 'Heating') This light illuminates when the heating element is active and heating the water. It will turn off once the set temperature is reached.
5.2 Initial Start-up and Heating
- Ensure the tank is completely filled with water (refer to Section 4.2).
- Plug in the power cable. The 'Power' indicator light will turn on.
- Set the temperature control knob to your desired setting (e.g., 'Eco' or 'Max'). The 'Heating' indicator light will turn on.
- The water heater will begin heating. The heating time for a full 15-liter tank is approximately 35 minutes to reach maximum temperature.
- Once the set temperature is reached, the 'Heating' light will turn off, and the unit will maintain the temperature by cycling the heating element on and off as needed.
6. Maintenance
Regular maintenance ensures the longevity and efficient operation of your water heater.
- Descaling: Depending on water hardness in your area, the heating element may accumulate limescale. It is recommended to have the unit descaled by a qualified technician every 1-2 years.
- Check Connections: Periodically inspect water connections for any signs of leaks. Tighten connections if necessary.
- Clean Exterior: Clean the exterior casing with a soft, damp cloth. Do not use abrasive cleaners or solvents.
- Safety Valve Check: The pressure relief valve (part of the inlet combination) should be checked periodically according to local regulations. Consult a professional for this procedure.
7. Troubleshooting
If you encounter issues with your water heater, refer to the following common problems and solutions:
| Problem | Possible Cause | Solution |
|---|---|---|
| No hot water | No power supply; Thermostat set too low; Heating element failure. | Check power connection and circuit breaker; Adjust thermostat to a higher setting; Contact service for heating element replacement. |
| Water not hot enough | Thermostat set too low; Excessive hot water usage; Limescale buildup. | Increase thermostat setting; Allow more time for reheating; Descale the unit (professional service recommended). |
| Water leaks from connections | Loose connections; Damaged seals. | Tighten connections; Replace seals if damaged. |
| Water leaks from pressure relief valve | Normal operation during heating; Faulty valve. | A small drip is normal during heating. If continuous or excessive, contact a professional to check the valve or system pressure. |
| Unit makes unusual noises | Limescale buildup on heating element. | Descale the unit (professional service recommended). |
If the problem persists after attempting these solutions, please contact customer support or a qualified technician.
8. Specifications
Detailed technical specifications for the Thermex H HIT 15-U Pro Water Heater:
| Feature | Specification |
|---|---|
| Brand | Thermex |
| Model | H 15-U |
| Capacity | 15 Liters |
| Power | 1500 Watts |
| Voltage | 230 Volts |
| Heating Time (approx.) | 35 minutes |
| Item Weight | 9 Kilograms |
| Product Dimensions (W x H x D) | 385 x 406 x 335 mm (approximate, based on description) |
| Mounting Type | Wall-mounted (Under-sink) |
| Connections | 1/2 inch |
| Special Feature | Integrated Pressure Limiter and Non-Return Valve |
| Maximum Operating Pressure | 8 Bar |
| Efficiency Class | B |
9. Warranty
Thermex provides the following warranty for the H HIT 15-U Pro Water Heater:
- Unit Warranty: 2 years from the date of purchase.
- Boiler/Tank Warranty: 5 years from the date of purchase.
This warranty covers manufacturing defects under normal use. Please retain your proof of purchase for warranty claims. The warranty does not cover damage caused by improper installation, misuse, neglect, or unauthorized repairs.
10. Support
For technical assistance, warranty claims, or further information regarding your Thermex H HIT 15-U Pro Water Heater, please contact your retailer or the Thermex customer support department.
When contacting support, please have your product model (H 15-U) and serial number (if applicable) ready.
