Ariston’s new unvented electric water heater

Ariston’s new unvented electric water heater

Compact, Italian design is at the forefront of Ariston’s new Andris Lux unvented electric water heater, which is also convenient and easy to install, providing hot water at all times of the day to suit a property’s needs.

The unit is fully compliant with the latest ErP legislation (with units rated up to ‘A’ class), and available in three over-sink and four under-sink units respectively. The 1.5kW, 2kW and 3kW under-sink models have capacities of 6, 10 and 15 litres, while the 3kW over-sink units are available with capacities of 10, 15 and 30 litres.

 The range has a contemporary aesthetic, with its distinctive design incorporating a prismatic shape to maximise capacity and save space. For added durability,it boasts a robust four-bolt flange, nickel-free copper element and TBS rod thermostat. Units also benefit from a waterproof structure and ELCB safety system to prevent electrical shock.

All models feature a central regulation dial with a wide range of temperature settings, located above a heating action LED. There is also an “E” economy setting, enabling optimisation of comfort alongside energy savings.

The following step by step guide provides an overview of how to fit a 10-litre capacity Andris Lux electric water heater:


  1. Unpack

Clean and prepare the work area, before carefully unpacking the Andris Lux from its box and check it is not damaged. Be sure to read the installation instructions thoroughly.


  1. Check the contents

Ensure all the fitting components are present. These are: the 6-bar pressure relief valve, the dielectric junction connections for the unit and the wall-hanging bracket.


  1. Fit dielectric junctions

Fit the dielectric junctions to the inlet and outlet water connections. These help protect the unit against corrosion. Using PTFE tape and silicon jointing compound on the inlet and outlet terminals will also help ensure a watertight fit. Tighten the junctions with an appropriate spanner.


  1. Hang the unit

Check the wall where the Andris Lux is to be mounted is strong enough to support the weight of the unit. Then, mark the wall where the unit is to be installed according to the instructions, before drilling and fixing the hanging bracket – ensuring it is level. Once securely in place, carefully mount the unit on the bracket. Check it is stable and level.


  1. Connect cold pipework

Turn off and isolate the cold water supply. Tee into the supply to make the connection and, if required, fit a pressure reducing valve and expansion vessel. Fit a 6bar PRV and connect the cold water supply to the appliance inlet. Secure the pipework with a mixture of compression and solder fittings.

  1. Connect hot pipework

Connect the hot water outlet on the unit to the domestic hot water system, using 15mm copper pipe going to an approved flexible tap connector.


  1. Install discharge pipework

Install the discharge pipe from the 6-bar pressure relief valve to terminate either into a drain or a point of safety outside. One method is to run the (sleeved) discharge pipe straight through the wall to a drain outside, conforming to G3 and British Standards. Another option, as shown here, is to run the discharge pipe through the wall via a tundish – this is done when unable to terminate at a safe location or if pipe lengths are excessive. In these circumstances, Ariston’s ‘Kit C’ tundish should be used.


  1. Connect the electrics

Unscrew and remove the fascia panel of the Andris Lux to access the electrics. Connect the 13 amp electrical supply to the water heater. The cable is threaded through the rear of the unit and connected as per the wiring instructions in the manual. The electrical connection is via a 13 amp spur – in most cases, a standard switched fuse spur is sufficient. Once connected, reaffix the fascia panel.


  1. Commission the unit

To start the commissioning process, turn on the cold mains water supply to fill the unit, allowing any air to flush through the pipework. At this stage, check all pipework thoroughly to ensure there are no leaks and that all connections are well made.


  1. Turn on the power

Switch on the electrical supply at the fuse spur. Set the temperature using the dial on the front of the unit – with the “E” setting available for economy mode. Allow the water to heat up – the heating lamp on the front of the unit will go out once the water has reached the desired temperature. The water will heat up within 15 minutes. Once this is done, open the hot tap and check hot water is available. The installation is now complete!


If you want to watch an installation video of the Andris Lux unvented electric water heater visit


For more information about Ariston’s electric water heating products, visit 

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