The Shower Doctor Surgery - Electric Showers Explained

This guide will give you a brief overview of electric showers, how they work, their main components and the most common faults that can occur. It is accompanied by a video guide, which you can watch below if you'd like to see for yourself what the components look like.

You can purchase all of these components and spares from website, and if you need any help identifying a problem with your electric shower, you can get in touch with our customer service team.

Important safety advice:

It is important to point out that before you do any work on your electric shower you must make sure there is no power going to the unit. This means switching it off using a pull cord or isolation switch and also turning it off at the fuse board. Only then is it safe to remove the cover so you can see all the components inside.

Now we will take a look at the main components within an electric shower. Of course, showers all look slightly different inside, but they will contain most of the same components.

The main parts:

The first component that the water meets when you switch on your shower is the solenoid valve. It is essentially an on-off switch for the water. Whenever there is power running through it, the coil energises and the water passes through.

The water then goes on through the stabiliser valve, or the flow control valve. In some cheaper showers, the stabiliser valve also does the job of the solenoid and there is no separate solenoid valve.

From the stabiliser valve there is a small pipe or adapter than takes the water up into the pressure switch. This is the part of the shower that recognises the water is turned on. As soon as there is water pressure inside the unit, it allows the electricity to flow through to the elements in the shower's heating tank. For the shower to work once the water is switched on there must be enough pressure to activate the pressure switch.

Next there is the flow valve, which alters the speed of the water through the heating tank and therefore also controls the temperature. The faster the water flows through the heating tank, the cooler the shower temperature. The slower it flows through, the hotter it gets as there is more time for it to heat up.

Power to the shower from the pull cord or the isolation switch comes in through the terminal block and on to the thermal cut-out. If for any reason the heating tank is too hot, then the thermal cut-out will shut off the power to the elements.

From the thermal cut-out the electricity passes on to the pressure switch where - provided there is enough water pressure - it is passed through to the elements in the heating tank.

Common faults:

Here we look at what can go wrong with each of the components and what the impact can be on your shower when they fail.

Solenoid valve

When this part starts to fail it usually just cuts the shower off completely after a few minutes before coming back on again a couple of minutes later.So if you find your shower turning itself off and on again, the solenoid valve is probably the culprit and it will need to be replaced with a new one.

Flow control valve

These components seldom go wrong. However, if you turn the shower from fully hot to fully cold and there is not a huge difference in the flow, that can mean you have a faulty flow valve.

Pressure switch

Because this is a moving part it is subject to wear and tear and can leak. You will therefore need to replace it with a new part.

Thermal cut-out

If the temperature in the hot water tank is too hot this part will cut out. If this happens on a regular basis the thermal cut-out will fail and will need to be replaced.

Heating tank elements

If one of your heating tank elements is faulty you may find that you lose flow when you turn your shower to its hottest temperature setting. This is because you are only working with one element. If the shower has no hot water at all, look at the thermal cut-out first and if there is some heat but not enough, consider the heating elements.

Watch the full video below:

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