Electric Shower Problems: 5 most common faults (and wha

This is a transcript of our YouTube video covering most common electric shower faults. Scroll below to watch the full video.

Here at The Shower Doctor, everyday we receive emails and phone calls from people that have faults with their electric shower, so what we are about to do here is run through the top 5 faults with electric showers and give you some idea of where to look to find where the problem is with the shower.

Number 5: The water is tepid, or there is just not enough power in the shower

The reason that the shower is tepid, or there is not enough power from it is perhaps because of the microswitch. This may have burnt out inside and not be allowing the power through to the elements. Indeed, it could be an element itself, if one of the elements inside heating tank has burnt out then the shower will only be working at half power. If you want to find out more about how to test a heating tank element, you can watch our dedicated video.

A typical electric shower microswitch damaged by heat.
A typical electric shower microswitch damaged by heat.


Number 4: My shower is going hot & cold

If your shower is going hot and cold, it's usually caused by not enough water getting to the shower. So first of all check that the valve coming into your house is fully open and the valve on the line to the shower is fully open. If they are both fully open, then it could be a problem with your showers flow valve inside the shower. If this is the case, they will need replacing. We cover this issue in a lot more detail in our dedicated video on hot & cold water cycling.

Flow valves from Redring and Triton side by side.
Depending on the manufacturer and shower model, a flow valve could be either a very simple, like the Redring valve above on the left, or a fairly sophisticated device, like the stabiliser valve/pressure switch assembly used in many Triton showers seen on the right.


Number 3: The shower is absolutely cold!

If your shower is absolutely cold, what could be causing it is the Thermal Cut-Out (also known as TCO for short), and what happens is if the shower overheats, this cuts off the power to the elements. If the shower overheats just a little, it cuts it off and resets. If this keeps happening though, or indeed the shower gets far too hot, it cuts out completely and will need replacing. We have a handy DIY video that shows you how to test and replace your Thermal Cut-Out.

Thermal cut-out on top of the heating tank.
Thermal cut-out (highlighted in red) typically sits right on top of the heating tank.


Number 2: There is water coming from the bottom of my shower

If you ever find there is water coming from the bottom of your electric shower, it may very well be that the PRD (Pressure Relief Device) has activated. All of the manufacturers have them and they are all slightly different in terms of shape and size, but most of the time, it's just a ball inside the PRD that gets ejected when the pressure builds up inside the heating tank. This is normally caused by a blocked shower head or a kinked shower hose. If you'd like to replace the PRD yourself, we have a video showing how to do just that - this particular guide is focused on a Triton shower model, but same principles will apply to electric showers from most popular manufacturers.

PRDs from multiple shower manufacturers.
Pressure relief devices come in many shapes and sizes and are sometimes an integral part of the shower outlet pipe assembly.


Number 1: There is no water coming from the shower at all, or it stops and starts

This is it, the most common fault with electric showers - the solenoid valve. If you find the shower stops working completely, or indeed cuts off (very often when you have soap in your hair) this is the culprit. It's usually the coil that breaks down. The coil (when working) lifts a plunger inside the solenoid valve and allows the water into the shower. When the coil breaks down, the water stops running and that's what causes the problem. As usual, we have a video that explains how to test and replace a faulty solenoid valve on our YouTube channel.

Typical solenoid coil sitting inside an electric shower.
Testing the solenoid coil is fairly straightforward with a standard multimeter: make sure the shower is switched off, multimeter is set to Ohms, then place the probes on the 2 coil terminals (highlighted in red). Generally, resistance reading between 3.5-4.0 kilo Ohms means your coil is fine.


You can also watch the full video guide below:

That wraps up our guide to most common electric shower faults. Even if your particular issue was not mentioned above, remember you can contact our customer service team for free and honest advice that can potentially save you hundreds of pounds on a plumber visit.

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