Isolator Switch For Shower Not Working? Here’s Why

Electric shower isolator switches are weird contraptions. They’re intended to stay out of the way until they’re needed. Used to shut off power to a shower for maintenance, they can develop a few problems when used regularly. Luckily, DreamyHome has dealt with this before and we can help get your problem sorted. Let’s talk about what can go wrong with an isolator switch for a shower, and what to do to fix those problems.

An isolator switch for a shower can fail when used often. Additionally, overheating can cause a number of issues when left unaddressed.

There are a few other things that could go wrong, so stay tuned to get all of the details. Let’s get right into it – there’s no sense in mincing words, right?

What is an Isolator Switch for a Shower?

Let’s start with the basics – what the heck are we even talking about? An isolator switch is, well, a switch that isolates your electric shower. While it can come in a number of forms, its function is rather simple. It cuts the shower off from your home’s electricity.

This allows you to perform maintenance without having to turn off the power at the breaker. It’s super convenient when performing repairs, and you’ll be thankful that you have one when it comes time to perform a repair on the electric shower. Whether it’s in pullcord form or works as a switch or button, an isolator switch works the same, regardless.

Difference Between an Isolator and Circuit Breaker

A common misconception is that an isolator switch and circuit breaker are, if not the same, at least similar. While it’s an understandable misunderstanding, it’s exactly that – a misunderstanding.

A circuit breaker acts as a shield to prevent excessive currents from making their way into your electronics. This protects them from damage and fire hazards, as well as provides a handy way to shut off electricity at the source for a set of outlets or devices.

An isolator, on the other hand, is designed with the idea that no current will be passing through them. This is known as a “no-load” position, and that’s important. A device designed to be in a no-load position should never be put into a loaded position for one important reason – they’re not made for it.

In addition, a circuit breaker is designed to operate independently (automatically, without command), while an isolator must be activated. So in short – a circuit breaker is the shield, and an isolator is essentially a master command to remove a part from the circuit entirely. Do not try to use them interchangeably, as it will damage the isolator and render it useless.

Now that we know what an isolator is, let’s talk about what can go wrong with them, yeah?

What Can Go Wrong?

There are a few things that commonly go wrong with electric shower isolator switches. They range from overuse to overheating, and more, but they’re luckily all relatively easy to resolve. Let’s take a deeper look at each cause (and what to do about them), shall we?


The most common cause of a failed electric shower isolator switch is overuse. Some people don’t quite understand what exactly they do, and this leads to misuse – and a lot of it. Generally, the big issue is that people treat it as an off switch – which it certainly isn’t.

The isolator switch isn’t designed like a light switch, where heavy use is accounted for. It’s a small, simple device that can easily wear and break. After all – it’s designed to be used maybe (at most) twice a year. If you’re in the habit of pulling that cord or flipping that switch when you’re done with the shower, please, stop.

Not only are you doing damage to the switch mechanism, but you’re wearing it out prematurely.


All it takes is a single faulty connection or frayed wire, and bam! Your isolator switch is overheated. One poor connection can cause much more serious problems than you likely realise – so it’s a good thing to keep an eye on.

If you open up your isolator switch mechanism and the area where the home’s wiring connects, look for melted or damaged wires and plastic covers. These are a surefire sign that something has gone wrong. Sometimes the solution is as simple as replacing the mechanism, other times you’ll need to hire an electrician to do a bit of rewiring.

Another factor that plays into both overheating and overuse is low-quality switches. If you pay a seemingly impossibly low price – it probably is. When it comes to electronics (especially those wired into your home) it’s generally best to aim for quality over cost. Should you install a low-quality switch, you’re more likely to run into wear and damage from a number of factors that a high-quality switch simply wouldn’t have to deal with.

What to Do About It

If your shower isolator switch is overheating, there’s a pretty simple response – replace the parts that are damaged. If it’s overused, do the obvious thing and stop using it every day. Either way, you’ll likely need to replace at least a single part – so here’s how to do it.

Start by turning off the power at your home’s circuit breaker. You really don’t want to be doing this with live wires. Having a surprise appointment at the cemetery isn’t ideal, especially if your headstone will read, “Here lies Jim – loving father, dutiful husband, terrible electrician. Don’t be like him.”

Next, open the cover to your isolator switch. It’s usually held in place by a metal cover and a couple of screws. Once you can see inside, it’s time to put on your detective hat.

Look for signs of overheating and damage – frayed wires, melted plastic or wiring, and (the obvious one) burn marks. None of these is good, and each insinuates the need to replace at least a single part.

Once you’ve located the cause of the issue, order replacement parts, ensuring they’re the proper replacement. Pop out the part in question and install the new one. You can now work in reverse order, reinstalling everything that was removed.

Final Thoughts

In today’s article, we discussed the basics of isolators, as well as what can go wrong with them. Whether it’s due to misuse, overuse, overheating, or cheap parts, an isolator can fail for a number of reasons. If your isolator switch has suddenly stopped working, though, don’t panic. It’s likely that you’ll need to simply replace a part or two. Worst case, you need to do some rewiring, which can often be done as a DIY project.

And if you’re ever uncomfortable with the work we talk about in this article, please – call an electrician. They’ll be able to get your isolator switch sorted in no time and will likely do a better job than you could. And don’t take that as an insult – they’re professionals, so it’s their job to be better than you at it.

Related Topics To Read Next

Crack in Your Shower Tray? Here’s What to Do

How to Increase Pressure in an Electric Shower

Electric Shower Flow Rate & Other Basics [Shower Basics Guide]

Common Thermostatic Shower Problems & Fixes

Shower Won’t Turn Off? Here’s Why

Shower Pump Not Working? Here’s why

How to Seal a Shower Screen

Airlock In Shower? Here’s What to Do

Triton Shower Low Pressure? Here’s Why

Triton Shower Not Working? Here’s Why

Aqualisa Shower Leaking? Here’s Why

Aqualisa Shower Problems? Here’s Why

Shower Screen Leaking? Try This

Mira Shower Leaking? Here’s Why

Shower Waste Fall & Other Basics

Shower Pipe Size – The Basics

About the Author Harry Thompson

Involved in home renovations throughout his life, Harry is an expert in everything to do with home and garden DIY. In his spare time, he enjoys cooking and tending to his garden.