Electric Shower - Fitting an Electric Showers

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All Wickes electric shower heaters are BEAB (British Electrotechnical Approvals Board) approved, ensuring safety and comfort whilst showering. They all work on the same principle which is that cold water, normally from the house rising main supply pipe, passes over one or more electrically heated elements in a container in the housing. The water temperature is controlled by the rate at which the water flows over the element.

The amount of water that can be heated to a desirable temperature is governed by three factors, (a) the ambient temperature of the water entering the unit, (b) the heating ability - wattage - of the elements and (c) the preferred showering temperature. Wickes heaters range from 7.5kW to 9.5kW

All Wickes electric shower heaters in the range have a temperature adjustment control which works by increasing or decreasing the water flow rate over the elements. All current models of Wickes electric shower heaters are fitted with the means of element selection or power control for even greater economy of use during warmer summer months.

During the winter months the ambient temperature of water entering the unit will be lower, so maximum heat will be required to heat the water to the desired temperature and the flow rate will be reduced. During the summer months the ambient water temperature will be higher thus requiring less heat from the elements to achieve the desired showering temperature. The flow rate will be greater. As an example, the flow rate from a 7.5kW heater will vary from approximately 2 litres / minute in the winter to 5 litres / minute in the summer. Selecting an electric shower heater with a higher kilowatt rating will provide improved performance throughout the year. As a guide:

8.5kW = up to 27% more flow than a 7.5kW heater

9.5kW = up to 42% more flow than a 7.5kW heater

It can be seen clearly from this information that more highly rated models will push out heated water under greater flow and you should bear this in mind when selecting the model for your property.

 

Comfort and Safety Features

In operation Wickes electric shower heaters benefit from stabilised temperature control. Whilst showering, mains water pressure can fluctuate when other outlets in the house served directly by the rising main are turned on. Under normal pressure changes that occur, flow remains virtually constant by an automatic adjustment of the internal temperature control valve, ensuring that a stable water temperature is maintained.

If the water pressure falls below the required minimum for it to be safe to heat the water, an integral pressure sensing switch turns off the heating elements until adequate pressure is available. The minimum water pressure required to operate all Wickes models is 1 bar running pressure, which can normally be achieved from the mains cold supply.

If it is established that mains water pressure is below 1 bar, an electric shower heater can be fed with water from a storage cistern, provided that the base of the cistern is at least 10 metres above the shower sprayhead. This is a considerable height not normally achievable in most homes.

NOTE: A single impeller pump suitable for use with an electric shower, which is capable of delivering the minimum pressures as above, can be used via a cistern to supply the shower where mains pressure is inadequate. However, a single impeller pump cannot be used to increase the output performance of a shower.

In addition to stabilised temperature and pressure sensing capabilities, electric showers are fitted with maximum temperature limiting switches to ensure that a maximum safe shower temperature cannot be exceeded. These switches operate automatically to turn off the heating elements if insufficient water is flowing through the unit. The unit resets automatically when the water temperature reduces to a satisfactory level.

 

Before You Start

Before fitting an electric shower it is important to check (a) that there will be sufficient water pressure to operate the shower and (b) that the electricity supply in the property will be adequate to cope with the additional loading.

Advice on plumbing skills can be found in Wickes Good Idea Leaflet 48.

Specialist tools should not be necessary to undertake the plumbing work, but in the interests of safety, it is advisable to use a mains tester when working on electrical circuits.

Materials required for the installation will vary but a guide follows.

 

Plumbing

15mm copper pipe and fittings will be needed to run a supply from a tee in the rising main to the heater inlet.

An isolating valve must be incorporated in this pipework. If there is any chance that the sprayhead could be lowered far enough to go into a bath tub or shower tray containing waste water, it will be necessary to fit a double check valve into the supply pipe to prevent possible back siphonage into the mains. This then complies with water Byelaws. All components are available from Wickes.

 

Electrics

The electric shower heater must be supplied with power directly from a fuse box or consumer unit. It cannot be supplied with power from an existing circuit. The supply should have RCD protection at the consumer unit.

Where an existing fuse box or consumer unit does not have a spare 'fuseway' for an additional circuit it will be necessary to fit a larger consumer unit with more fuseways. Alternatively, you can fit an additional small consumer unit. In the latter case you will need a 'service splitter' and your electricity company will need to connect the meter tails to this.

The fuse or MCB required will depend upon the rating of the chosen shower heater and the heater installation instructions will guide you towards the correct selection. MCBs will range from 32amps for a 7kW heater up to 40amps for a 9.5kW heater. A 10.5kW requires a 45amp MCB.

Cable will be 6mm2 or 10mm2 twin and earth depending on site factors. Only a qualified electrician will have the expertise to calculate when 10mm2 cable will be needed.

If replacing an existing shower unit with a higher kilowatt unit, it is essential to ensure that the electric cable is adequate for the increased load.

You will also require a 45amp double pole isolating switch in the cable run. If this is to be located in the bathroom it must be a pull cord operated type.

Everything is available from Wickes

All electrical works MUST conform to BS767 the current IEE Wiring Regulations and Part P of Building Regulations. You are advised to check with your local authority's Building Control Department, or an Authorised Competent Person before starting.

A direct replacement, without a wiring change, need not be notified to your local Building Control Department. If in any doubt about electrical work, call in a qualified electrician.

FIG. 1 shows a very basic layout. New installations will have to be compliant with Part P of Building Regulations

 

Installation

Very comprehensive installation instructions are supplied with the shower heaters but briefly, your first task is to determine where to locate the heater unit. It can be in a shower cubicle or over a bath but cable and pipe routing must be carefully planned. In all cases the shower must be fixed to a finished surface. Do not for example fit the unit and then try to tile up to it.

It should be fitted at a height where it will only be subjected to normal degrees of splashing water whilst showering.

Plumbing should precede wiring to ensure that water leaks on commissioning can be rectified before any electricity is present inside the unit.

 

Features of each Shower Heater

Apart from the comfort and safety features already outlined and which are common to all units, each has its own individual special features.

 

Helpline

In the event of installation or usage problems please contact the Wickes Customer Care Helpline on 024 7632 8341

 

Aquatronic 1+ Product Code: 160-504 (7.5kW) 207-295 (8.5kW)

Aquatronic 2 Plus Product Code: 207-296 (8.5kW) 207-297 (9.5kW)

Aquatronic 3 Ultra Product Code: 160-507 (8.5kW) 160-508 (9.5kW) 207-298 (9.5kW Satin Grey)

Aquatronic 4 Ultra Product Code: 207-299 (9.5kW White) 207-300 (9.5kW Chrome)

Aquatronic Style Product Code: 207-301 (9.5kW)

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