How to install/replace an electric shower

Electric Shower Installation

When installing an electric shower, before doing anything, make sure that you have turned off the power supply to any circuits connected to the area of installation at the consumer control unit. Also, ensure that all electrical fixtures are properly earthed. As you would expect, we would recommend consulting your local electrician before attempting such an installation.

1. Plumbing requirements

The first option would be to connect the shower to the mains water supply. In which case, the shower should be connected to the mains cold water feed using a 15mm diameter pipe, with a minimum running pressure of 0.7 bar. Additionally, you will need a static pressure of at least 1.0 bar and a minimum flow rate of 8 litres per minute. However, make sure that you check the installation manual of your shower model as these details may vary.

If it’s not possible to connect the shower to the mains water supply then a second option would be to connect the electric shower to a pumped tank-fed supply. Therefore you will need a cold water storage tank. You will also need to install a single impeller shower pump. In order to activate the pump you will need a minimum flow rate of 1 litre per minute. However, some electric showers have devices (solenoids) built-in which prevent water flowing through the shower at a natural rate. Therefore you will need to install a negative head pump in order to regulate the pressure between shower unit and the pump. In most cases a 2.0 bar pump will normally suffice. Before installing such a pump, be sure to check your showers installation manual for details.

2. Electric shower requirements

Before installing your electrical shower you will first need to ensure that your consumer control unit (electrical energy distribution board) has a sufficient power rating for your electrical shower unit. You cannot take the power supply from an existing circuit or ring main and so you will need to install a separate cable from the consumer control unit to the electrical shower directly. It is also important to double check the fuse rating of the main fuse. Please ask your electrical supplier if you are unsure. You will also need to consider how many electrical appliances you will have running at the same time. You’ll then know whether your fuse rating will allow for an additional 7kw shower. If you don’t have a spare “Way” on your consumer control unit we strongly suggest that you contact your local electrician as it can be costly to install new a unit and may be more appropriate to consider an alternative option such as a simple mixer-tap electric shower.

When installing an electric shower you will also need to install a Local Isolating Switch. This is also referred to as a “double pole isolating switch”. This switch needs to be out of reach from the shower/bath area and is required to turn the power off when the shower is not in use. It is also helpful when it comes to repairing, maintaining and replacing the shower. The cable size will depend on the power of the shower and the length of the cable run. Avoid running the cable too close to hot water pipes to ensure the cable doesn’t get damaged. In any case, please feel free to contact us for some friendly advice.

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