The supply company says it is investigating reports of discoloured water from some users in Llangollen today (Tuesday).
A statement on the Dee Valley Water website says: "Please note that if you live in the Llangollen area you may be experiencing problems of discolouration to your water supply.
"Our Network Inspectors are currently investigating this issue to try and resolve this matter as soon as possible.
"If your water supply is discoloured we would please ask that you refrain from using the supply for any water appliances until the supply has cleared and it may help if you run the kitchen cold water tap to try and clear the supply.
"Please accept our apologies for any inconvenience caused as a result of this disruption and be assured that we are doing everything possible to restore the supply to normal.
"We will keep our website updated with the latest information."
The website to check is: http://www.deevalleywater.co.uk/news.php?id=80