Tap water that’s been discoloured for a few hours or days

Quick check list

My tap water may:

  • look black, brown, orange, red or yellow in colour
  • look clearer after I run the tap for a while
  • have been turned off recently
  • be at a lower pressure than normal
  • be discoloured at all taps in my house
  • be discoloured in my house and at my neighbour’s.

What causes it?

We may have been working on your water mains network, perhaps fixing a burst main, and stirred up some iron sediments. If this is the reason, it’s normally short-lived and shouldn’t last more than 24 hours. Although these iron sediments aren’t harmful, we appreciate the water might not look very pleasant.

What can I do?

As the discoloured water’s already in the pipe, you need to let it work its way through the system. 

  • Try running the taps for 30 minutes or more
  • Check out In Your Area to see if there’s been any activity in your neighbourhood
  • Don’t do any laundry; the discoloured water may stain the washing. If this happens, keep the washing damp and give us a call
  • If it’s been longer than 24 hours, we need to flush the water mains to help it along its way. Give us a call and we’ll endeavour to fix the problem
  • Sometimes the internal plumbing can cause discoloured water, see below for more information
  • If your water looks different to the description above, or it has a funny taste or smell, give us a call and we’ll investigate further.

What are we doing about it?

We have a maintenance programme for our network of water pipes, which helps keep the water mains free of iron sediment; the main cause of discoloured water. We do this by stirring up and flushing out all the sediment and we’ll always let you know before we start.

Have you flushed your taps to remove discoloured water? If you’re on a meter call us and we’ll give you a £2 flushing credit towards your next bill - this equates to the cost of filling five bathtubs.


If you run off any water from your taps, don’t waste it, collect and use for watering houseplants or in the garden.

Tap water that’s been discoloured for a few weeks or months

Quick check list 

My tap water may:

  • looks black, brown, orange, red or yellow in colour
  • looks clearer after I briefly run the tap
  • only be discoloured at one tap
  • be discoloured in my house, but my neighbour’s water looks ok.

What causes it?

If you live in an older property, you might have iron pipework, plumbing or tanks. Sometimes these can start to rust and the iron sediments will discolour the water. 

What can I do?

Sometimes a quick plumbing check can identify the problem.

  • Check where the tap is fed from. If it’s supplied from a tank then this might need cleaning or even replacing. Ensure your tanks have well-fitting lids too
  • If the affected tap is fed straight from the water main outside, but your neighbour’s water looks fine, your supply pipe might be causing the problem. See below for instructions on how to check this
  • If you still have trouble fixing the problem, get some advice from an Approved Plumber or give us a call and we’ll do our best to help.

How do I know if I have an iron pipe?

It just takes a few minutes to check:

  1. find the point where the water pipe enters your property – it’s usually at the internal stop tap, typically under your kitchen sink or in the downstairs toilet
  2. unpainted iron pipes are grey or brown (rusty) in colour
  3. check with a fridge magnet – if the pipe’s iron, the magnet will stick to it.

How can I replace my pipe?

If you’d like to replace your pipe, fill in the online form and we’ll arrange to connect a new supply pipe to the water main. 

Whenever you alter or replace pipework in your home, ensure you only use approved materials and an approved plumber or underground installer. Find out more about our Approved Plumber Scheme

Our Connections Team is happy to advise on the best way to replace your pipe. Call us on 0345 60 66 087.

Still stuck?

If your water looks different to the description above, or has a funny taste or smell, give us a call and we’ll investigate for you.

Try our self diagnosis tool to help solve the problem. 

If you’re a business customer, contact your provider for more information.