My shower temperature fluctuates or is only running hot or cold — what’s wrong?

Inconsistent or incorrect water temperature is usually caused by limescale, unbalanced water pressure, or a faulty thermostatic cartridge. If you are experiencing water that is too hot or too cold due to an imbalanced water system, temperature fluctuations mid shower, or a valve that is not mixing water properly, the following steps will help to remedy the issue:

1. Turn off the water supply.
2. Remove the handles, trim plate and extract the thermostatic cartridge. Instructions for your product can be found by selecting the relevant product on our website and navigating to the 'Downloads' tab on the product page.
3. Check the cartridge for any scale or debris build up
4. Soak in descaler (e.g. white vinegar) for 30 minutes and then wash through with water.
5. Return the cartridge to the valve and replace the handles and trim kit.
6. Test by adjusting between hot and cold for smooth temperature control.
7. If temperature remains inconsistent, fit a new thermostatic cartridge.

Tip: For homes in hard-water areas, descale the cartridge every 12–18 months.

New cartridges can be ordered via our official spares website. Ensure compatibility by matching the product image or part code.