Severn Trent Water customers in postcode areas including Bentley, Short Heath, Wednesfield and Bilston were affected on Friday morning.
A Severn Trent spokesperson stated: “We would like to offer our sincere apologies to residents in Wolverhampton who experienced intermittent supply issues today.
"This was the result of an issue with a specific piece of equipment on our network which has now been resolved and all customers should now be back on supply.”
The company said the disruption was not linked to its pipe laying project in the Fallings Park area of Wolverhampton.
A customer text message added: "We’re really sorry to hear some of our customers living in Wolverhampton area may be experiencing some supply interruptions this afternoon.
"The issue has been resolved however, the main is currently 'recharging' meaning that over time your supply will improve, gradually returning back to normal. We thank you for you continued patience."