Top 3 Reasons Why Electrical Showers Go Hot And Then Cold

There is nothing worse than enjoying a hot shower and getting blasted by cold water! Here’s how to avoid this shocker for good!

When electrical showers run hot and then cold, three things could be responsible. These causes include limescale, problems with water pressure, and electrical faults.

This is a truly annoying problem. Worse, it could lead to worse damage if not fixed in due course. We provide all the information you need to identify and fix the problem.

READ NEXT: This is why your shower has no cold water.

Why Is My Electric Shower Going Hot Then Cold?

As popular as electrical showers are, they can be prone to particular problems. One of them is particularly frustrating. You are enjoying your hot shower when suddenly, a jet of cold water hits you. This is really uncomfortable, to say the least. A lot of people also shower before work and this could prove to be a little problematic.

Before we start, remember that you need a good grasp on basic DIY skills to fix an electric shower. Otherwise, do not hesitate to seek out the services of an electrician or plumber. A professional can save you time and the frustration of trying to identify the problem.

The top 3 reasons why this problem occurs include:

  • There is a build-up of limescale.
  • Problems with the water pressure.
  • Electrical faults.

Are you interested in adding your first or second electric shower? Find out how much it costs to install an electric shower.

There Is A Build-Up Of Limescale


Limescale is something that plagues all appliances that work with water. Items affected include dishwashers, washing machines, ironing equipment, plumbing, showers, and taps. Electric showers are also vulnerable. Limescale is basically layers of mineral deposits that are caused by hard water (this term refers to water with a high mineral content).

You can find out if you live in a hard water area and if you do, then the chances are that your shower has a limescale problem.

Get all the best tips and tricks from our free guide that explains how to clean an electric shower.

How Do I Fix A Limescale Problem?

If your shower already has limescale – and the grey or green deposits are easy to spot – then you can use a descaling cleaner. But the best policy is prevention. You can completely avoid this problem when you make a habit of descaling the water canister on a regular basis.

Descaling helps to get rid of the limescale that affects the pressure of the water in the hot shower. If descaling fails to work, then you might need to replace the entire unit. If you want to lengthen the time periods between descaling, you can install a magnetic softener in the inlet pipe. You can also add a water softener to the mains water supply of your home to protect all your water-using appliances from limescale.

Do you love the technical side of things? Then find out more about how an electrical shower works.

Problems With Water Pressure At The Shower Inlet

This is one of the most common things that might cause your electric shower to go hot and then cold.

To function normally, the water pressure for an electric shower needs to be about 1.5 bar static and 1.0 bar running pressure. The best way to test the water pressure is to use a hand-held pressure device that can be cheaply obtained from a hardware store. Otherwise, you can also listen for a clicking sound inside the unit. If you hear any clicking noises, there is a chance that they are being caused by low water pressure.

Read Next: Shower pump not working? Here’s why.

But what causes water pressure to drop? Your local municipality could be fixing a pipe somewhere and it will only temporarily affect your shower. You don’t need to do anything in that case. The pressure at the inlet could also drop because of a clogged mesh or a malfunctioning valve. Both of these can be fixed pretty easily. You can either replace the mesh and/or the valve or clean it up to get rid of the clogging debris/particles.

If you are also experiencing sudden cut-outs, then we have another article that explains why your electric shower keeps cutting out and how to fix it.

powerful electric shower

How To Deal With Electrical Faults

Another possible cause occurs when, for some reason, the heat can is ground to earth in a similar way to an oven’s heating. If this is the case, the only way to fix it is to replace the heat can. This is one of the problems that would require an electrician to troubleshoot because it is difficult – and possibly unsafe – to try and fix it yourself.

It is worth noting that this is not the only electrical fault that could be causing an electric shower to go from hot to cold. This is another reason why an electrician is a must. They can do a thorough examination of the shower and find the problem or problems.

This hot to cold scenario is not the only temperature problem that you can encounter. Learn more about why an electric shower runs cold.

A Quick Summary On Why Electric Showers Run Hot Then Cold

  • Electric showers are hugely popular because they provide as much hot water as you need.
  • These showers have a few hiccups and one of the most annoying is when the hot water suddenly turns cold.
  • There are three common reasons why electric showers go from hot to cold water in an instant.
  • These reasons include a limescale build-up, there might be a problem with the water pressure or the shower might be experiencing electrical faults.
  • Limescale can be removed with a descaling agent.
  • A good cleaning routine will also prevent limescale.
  • Adding a water softener device to the waterline can also prevent limescale.
  • Low water pressure can be rectified by cleaning or replacing the mesh and valve.
  • Electrical faults must be dealt with by a qualified electrician.

READ NEXT: Learn more about why your boiler is clicking (and other noises).