Mira Sport Shower Problems? Here’s Why

Electric showers are perhaps the 21st century’s most convenient invention yet. They allow us to take cold water and convert it to a steamy shower in mere seconds… until they stop working. Like all things in life, your fancy electric shower is bound to eventually run into a few issues. Luckily for you, DreamyHome is here for you. If your Mira Sport shower has problems, we’ll get you sorted in no time – so stay tuned.

The most common causes of Mira Sport shower problems are a dirty or damaged showerhead or hose, a failed thermal switch, blown Pressure Relief Device (PRD), a faulty solenoid in the flow valve, or limescale buildup in the heater tank.

That was a lot of information all at once, so let’s break it down into bite-sized chunks, shall we?

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Electric Shower Problems: The Basics

Electric showers are complicated machines. That means that there’s a lot that can go wrong in a very short amount of time. Let’s recap what can go wrong and give a few basics on what it actually means:

Limescale and mineral buildup –

This is something that’s bound to happen to your shower at some point, especially if you live in an area with particularly hard water. Over time, the minerals present in the water of your home will settle and harden onto whatever they come into contact with. That includes the showerhead, hose, and the actual heater tank. Luckily, it’s pretty simple to clean off (but we’ll get to that).

Thermal Switch

This is the device that’s used as one of the primary safety features in an electric shower. Should it fail, you may notice the hot water turning cold (as if it’s being drawn by another tap) – but it will get worse over time. Eventually, you’ll be left with no hot water. This is a repair best left to a qualified electrician, but again, we’ll get to that.

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The Pressure Relief Device (PRD) in your electric shower does exactly what it sounds like. In short, it prevents the pressure in your heater tank from building to dangerous levels. If the pressure is inable to be released, the PRD blows, releasing pressure that’s developed and keeping you safe. This pressure can be caused by the aforementioned limescale/mineral buildup, a failed/kinked shower hose, or an increase to the cold main’s supply.

Solenoid & Flow Valve –

This is (for all intents and purposes) your shower’s on/off switch. When power passes through it, the coil activates and allows water to pass. It then goes through the flow valve and to the pressure switch, eventually bringing you heated, high pressure water. Should this fail, you’ll need to likely replace the solenoid – though it’s often more cost-conscious to replace the flow valve entirely, as they come with a solenoid… usually.

Okay – you know what’s what. Now it’s time to clean and fix your shower.

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Fixing the Problem

First things first – a warning. Electric showers combine water and electricity, which can be a deadly combination. If you are not extremely confident in your ability to perform these repairs (beyond cleaning limescale) and remain uneletrocuted in the process, hire a professional or ask a friend who can do it for you. You do not want to be the guy whose headstone reads, “Here lies Joe; loving father, wonderful husband, terrible electrician… What a Schmoe.”

With that out of the way – let’s talk about fixing your problems.

Limescale Buildup

Especially as this can lead to some of the other problems we’re going to address, let’s start with the simple fix – cleaning up your shower. If there’s a limescale buildup in your heating tank, I’ve got bad news. Experts recommend replacing the entire tank, rather than trying to clean it out. You run the risk of damaging the tank and causing further issues, which isn’t really ideal.

However, you can easily clean your showerhead with a couple of household items – don’t bother with the commercial products that are generally offered. They do the same thing for more money.

You’ll need white distilled vinegar (the cheap stuff), 1-2 tbsp of baking soda, and time. A bobby pin or paperclip helps, too.


  1. Turn off the water to your shower and drain the showerhead. Fill a bowl with 1-2 litres (enough to submerge the showerhead) of vinegar, and a tablespoon of baking soda.
  2. Soak the showerhead for 30 minutes to an hour, then scrub. Use the paperclip to scrape pesky bits off.
  3. Repeat until the showerhead is clean.
  4. Test. If it still doesn’t work, replace the showerhead/hose as needed.

You can go here for more information and tips on cleaning.


Okay, once again, if you’re inexperienced with electrical work, just don’t attempt this. If you’re dedicated to doing so, here’s what to do:

  1. Turn off water at the main, as well as power at the circuit breaker.
  2. Take off the front cover of your Mira Sport shower.
  3. Locate the PRD. It’s generally near the outlet pipe, sometimes directly at the bottom. Take a photo of how it’s all installed.
  4. If it’s screwed in place, unscrew the PRD and remove the old O-ring.
  5. Replace the O-ring (which should come with a replacement PRD) and screw in the PRD. Ensure everything matches up with the photo you took, then turn the power and water back on.
  6. Test.

Thermal Switch

This is a repair best left to a professional. It is something that can be done at home, but it is both dangerous and complicated – if you’re not experienced with electrical work, do not attempt this repair.

Solenoid & Flow Valve

First things first – take the following safety precautions:

  1. Turn off power at the isolator switch/main circuit breaker
  2. Remove the related fuse from the fuse board.
  3. Turn off the main water supply.

Now – it’s time to check the solenoid. Take a multimeter and locate your solenoid. It should be at the bottom of the shower unit, made of a detachable coil and the valve itself. Attach the multimeter probes to the terminals on the valve and test – if it comes out to 3.5-4 Ohms, you’re in the clear. If not, it needs to be replaced.

Remove the coil by gently prying it out of place with a screwdriver (or two), gently twisting as you do so. Take a photo of the wires and then disconnect them each – carefully.

Reattach your replacement coil, following the setup your photo shows. Place it back into its slot and you should be set – be sure it’s settled before reattaching the cover. Now turn everything back on and test your shower!

Final Thoughts

Electric showers are complicated and potentially dangerous to repair – but it can be done, as we showed above. Be sure to always start with simple fixes like descaling your showerhead and replacing the hose/head as needed. Following that, you can move onto the PRD, solenoid and flow valve, and thermal switch.

If you’re inexperienced with electrical work, I highly recommend that you hire a professional to perform these fixes. If you make even one mistake, you run the risk of potentially lethal electrocution – and that’s, to say the least, no fun at all.