Are you tired of a low-pressure shower due to a faulty Mira Atom shower cartridge? Don’t let a clogged or worn-out part dampen your bathing experience. Replacing the cartridge might seem daunting, but with the right instructions, it’s a manageable task. Let’s guide you through the process step-by-step.
Before we dive in, ensure you have the following tools and materials ready: a flathead screwdriver, an adjustable wrench, a Phillips screwdriver, and the new Mira Atom shower cartridge.

Preparation and Cartridge Access
Before starting, ensure the water supply to your shower is turned off. You can find the isolation valve near your shower or in your loft. Once the water supply is off, open your shower valve to relieve any remaining water pressure.
Next, prepare your work area. Lay down a towel or cloth to catch any drips and reduce clutter. Now, let’s access the cartridge.
Removing the Old Cartridge
Starting from the top, use your flathead screwdriver to remove the operating cap. You might need to wiggle it or gently pry it off. Once off, you’ll see the temperature control panel.
Now, using your Phillips screwdriver, remove the two screws securing the temperature control panel. Carefully lift the panel off, exposing the cartridge. Use your adjustable wrench to Loosen the gland nut counterclockwise. You might need to break the seal, so be prepared for a bit of resistance.

Cartridge Removal and Replacement
Once the gland nut is loose, pull the cartridge out from the hole. You might need to rock it back and forth a bit. If your old cartridge is stuck, you could try using some penetrating oil to help loosen it up.
Now, take your new Mira Atom shower cartridge and follow the above steps in reverse. Ensure the groove on the cartridge aligns with the tang in the valve body. Hand-tighten the gland nut, then use your adjustable wrench to give it a quarter to half turn clockwise. Be careful not to overtighten.
Reassembling the Shower and Final Checks
With the new cartridge in place, replace the temperature control panel and secure it with the two screws. Then, replace the operating cap.

Now, turn your water supply back on at the isolation valve. Go to your shower and turn the tap on to check for any leaks. If everything is tight and there are no leaks, your shower is ready for use.
First Shower and Testing
Take a quick shower to check the replacement was successful. The water pressure should be back to normal, and you shouldn’t experience any issues with temperature mixing.
After your shower, wait a few minutes, then check the area where you replaced the cartridge for any leaks. If everything is working as expected, your Mira Atom shower cartridge replacement is complete!
Remember, if at any point you’re unsure, it’s always best to seek professional help to prevent further damage. Regular maintenance can extend the life of your shower and prevent issues like this in the future. Happy showering!








