Blue, pink, green or other coloured water

If your water is blue, pink, green, or any other unusual bright colour, please do not drink or use your water for cooking. Find out more information on common causes in the sections below: 

  • A blue/green tinge to your water can indicate elevated levels of copper in your water. This can be more common where there is relatively new copper plumbing in use on your property, in both new houses and older houses where new plumbing has been installed. This is because the new copper pipes are settling in, and after a few days a protective layer should form on the inside of the pipe, which will stop this.

    However it can also occur with old and corroded pipes, or where too much flux has been used to install the pipe or it may indicate that there is a problem with the electrical earth bonding. You should contact your house builder or a professionally qualified plumber for help.

  • On rare occasions, coloured water can be caused by poorly installed toilet cisterns, which allow water from the cisterns to flow back into the internal plumbing. This can only be apparent when coloured disnfection products are used directly in the toilet cistern. You may notice this if there has been an interruption to your water supply, or if the property has been empty for a short time such as a holiday. If you believe the blue water is being cause by back flow from your toilet cistern, a plumber will be able to help you solve this.

  • Algae can cause a green colour to water, however this would normally only ever occur in properties with header tanks when regular maintenance checks are not completed. If you think this may be what has caused your issue, have your regular maintenance checks completed.

  • To reduce the chances of these issues happening, you should:

    • Always use an approved plumber when carrying out work in your property

    • Flush through new pipework thoroughly

    • Only use lead-free flux 

    • Drain down plumbing systems which are not used immediately after installation.

    • Always ensure maintenance checks are up-to-date on all appliances on your property.

    You may also experience coloured mould or slime forming on things that come into contact with water, view our slime and staining page for more information.

    If you have any questions, please call our friendly team on 0345 672 3723. Dial 18001 first if you have hearing or speech difficulties.