Electric Shower Guide For Buyers
Electric showers are incredibly popular in many houses today. However, you need to be sure that it is the right choice for you, as there are so many different options out there.
In this guide, we will help answer some of the most important questions you have, such as:
- How do electric showers work?
- Who are electric showers best for?
- What requirements or regulations are there for electric showers?
- How powerful are they?
- What wattage do you need, and;
- Who should install them?
Get reading to find out everything you need to know about buying an electric shower...
Electric Showers Explained
Electric showers can be used in any domestic water system. They are versatile, easy to install and can even help you save energy. But, we imagine you will want a little more explanation than that!
For a start, how do they work? Who benefits most from them? What options are available?
Let’s take a look...
How do electric showers work?
In a nutshell, electric showers work by heating water very quickly over an electrically-charged heating element. Think of it as a kettle, albeit a very fast one!
Electric showers only need a cold water feed to work. Unlike mixer showers, which take a hot water feed straight from your boiler, an electric shower can be connected straight into your mains water supply. This makes them incredibly versatile when it comes to installation.
Do I need an electric shower? Who are they best for?
There are various reasons that many people choose to install an electric shower in their bathroom. Here are some of them:
- They have a small hot water tank. As mixer showers and power showers rely on your boiler for hot water, those with smaller tanks sometimes find they don’t have enough hot water to serve the whole household come shower time. Electric showers solve this problem as they produce their own hot water
- They are building a new bathroom. If you want to create a whole new bathroom, you might find it a bigger job if you need to connect your shower to your hot water supply. It’s much easier to get access to your cold water, which is all an electric shower requires.
- Instant hot showers. You don’t need to wait for your hot water to be on to have a shower when you go electric. They instantly heat your water up on-demand, so there’s no waiting around.
- There is a potential for energy saving. Electric showers only heat up the water you actually use. So, especially for smaller households, this can translate into a lower energy bill. They also have a lower flow rate, which can help those on water metres save, too.
- Their house has a combi boiler. Electric showers are suitable for pretty much any type of water system. However, they are an especially popular choice for homes with combi boilers. Those with gravity-fed systems often prefer a mixer shower or power shower.
Find out more about the different types of showers here.
There are a few important requirements you also need to know about before installing an electric shower:
- The water at your mains entry must have a minimum running pressure of 1 bar
- Your water must flow at a rate of 8 litres per minute
- It should also have a maximum static pressure of 10 bar
Most electric showers will be configured for these water bye-law stipulations, but it is as well to check with the manufacturer's instructions.
Not sure what all this means? Consult with a plumber to find out more before you buy your shower.
Is a power shower the same as an electric shower? What is the difference?
One question that often causes confusion is what the difference is between a power shower and an electric shower. One main difference lies in how water is fed into your shower:
- With an electric shower - only cold water is fed into the shower. Some of this water is passed over an electrical heating element and then mixed back in with cold water to reach your set temperature.
- With a power shower - both cold and hot water from your boiler tank is fed into your shower, then mixed together to reach your set temperature.
The other main difference is that power showers also use an electric pump to increase water pressure. Electric showers rely on the pressure of your mains water supply only - which doesn’t use a pump.
If you do want to connect your electric shower to a shower pump, you can only do so if you don’t have a combi boiler. Pumps should only be used with low-pressure water systems. If you suffer low water pressure, pumped electric showers are also available which can be used with a cold water tank supply - however, they too must not be plumbed straight into your mains water supply.
Take a look at our Common Questions About Shower Pumps blog for more information.
Can you get a powerful electric shower? What wattage do I need?
When shopping for an electric shower, a common concern is finding one that is powerful enough. The key here is the kW rating of your shower. Generally, the higher the kW rating, the more powerful your shower will be - both in terms of pressure and temperature.
Electric shower kW power ratings explained….
What is the kW rating of an electric shower all about? What does it mean, why does it matter and how do you know which one to choose?
Let’s return to our lesson on how electric showers work for a minute. The cold water is passed over a heating element. The temperature control dial on your shower actually controls how long cold water is passed over the heating device for - the longer, the hotter.
So, when you increase the temperature setting, you might sometimes notice a slight dip in pressure as the water flow slows down to increase heat.
This is where the kW rating comes in. The higher the kW rating, the faster your shower can heat water to a hotter temperature. This means that the water can maintain a more consistent pressure - resulting in a better shower experience!
What is the most powerful electric shower?
Electric showers vary in power. The lowest power is usually 7.5kW while the highest is generally 10.5kW. Higher wattage electric showers are often considered to be better, though the wattage you choose depends on how much you want to spend; higher-powered options usually cost more.
It also depends on what electric cable you have to wire up to it, which we will explain more about below…
What size cable and pipe is required for an electric shower?
The next thing you need to consider when buying an electric shower is what size cables and pipes you have to connect to your shower. This is where we get into the technical stuff, so if you are not sure, speak to a plumber.
Electric shower water pipe requirements
Your shower must be connected to the mains water supply via a 15mm water pipe. It is also a good idea to install an isolation valve in this run. This allows you to turn the water supply to the shower off if there are any problems or maintenance issues.
Electric shower cable requirements
The size of the wiring you will be connecting to your shower has a big impact on which shower you can buy. You need to know what size cable you have - remember, the measurement refers to the cross-section, not the length! Many cables have this printed on the outer insulation.
Always make sure you turn the water and power off before taking a look at your electric shower wiring.
Here are the usual guidelines for shower units within 18 metres of a fuse board...
- Showers up to 7kw may carry a 6mm cable. Fuses and switches should be rated at 32 amps.
- Showers up to 9kw may carry a 6mm cable. Fuses and switches should be rated at 40 amps.
And here are the usual guidelines for shower units within 35 metres of a fuse board...
- Showers up to 9.5kw should carry a 10mm cable. Fuses and switches should be rated at 45amp
- Showers up to 12.5kw should carry a 10mm cable. Fuses and switches should be rated at 50 amps.
In the past, older electric showers usually only have wattages up to 7.5kW. As modern showers have improved, the higher wattage means larger cables are required. For this reason, if you are replacing a very old electric shower, you might find rewiring is required.
Because of the important safety regulations surrounding electrical bathroom appliances, it is vital that the job is done by somebody who knows what they are doing. This leads us on to our next question...
Do I need a plumber or an electrician to fit an electric shower? Is it safe to do it myself?
Electric showers can seem to offer a conundrum - you need a plumber to connect it to a water supply, but surely you need an electrician to make sure that the wiring is safe?
You would be completely right to think this. Electricity and water can be a dangerous combination, so it’s important to get your shower installed properly to ensure you are safe.
Ideally, a Plumber with a Part P certification is the best person to do the job. This means that they are qualified to self-certify their work in accordance with the number of safety requirements that surround electric showers.
If you are replacing an electric shower like-for-like, it is possible to do it yourself. However, unless you have a Part P certification, it is always safer to get a professional tradesman in.
Find out more about how to replace an electric shower here.
However, don’t be scared off from buying an electric shower! There is no danger in using them, and they are completely safe when fit by a competent installer.
We hope this guide has helped you decide whether an electric shower is best for you!
Don’t forget, we stock a fantastic range of showers online at Plumbworld - all with exceptional prices and free next day delivery.
For more advice and information, visit the Plumbwolrd blog for posts like these…