A WATCHDOG has told four water firms they need to tackle high levels of complaints over service disruptions and billing problems.

The Consumer Council for Water (CCWater) is demanding urgent improvement from Thames Water, Northumbrian Water, Essex and Suffolk Water and Hafren Dyfrdwy, as well as quarterly reports highlighting what action they have taken and what more they plan to do to reduce complaints.

Thames Water, England's largest supplier, had a 24% increase in written complaints over the last year, while 10 per cent more customers had to phone to resolve an issue.

However, the company have said a number of customer service improvements across the business have helped Thames Water cut complaints by 10 per cent since April.

The improved performance follows last year’s Beast from the East, which froze and cracked pipes, and summer heatwave, which led to an unprecedented increase in demand for water.

Kelly Macfarlane, Thames Water customer experience director, said: “The combination of these factors over the course of a year created a perfect storm that had an unacceptable impact on our customers.

"We feel and regret that deeply, and have already taken action to improve service and get things right first time for our customers when they need us.

Problems sparked by the rollout of a new billing system were the main cause of a spike in calls and written complaints to Northumbrian Water and Essex and Suffolk Water, which are part of the same company.

The changes meant customers had longer waiting times or saw their calls abandoned, leading to a 64 per cent rise in written complaints to Northumbrian Water while Essex and Suffolk's more than doubled.

Across all companies, almost half of customer grievances related to problems with their bill or charges, but there was also a 28 per cent rise in complaints about water supply and pressure as suppliers struggled to cope with the bitterly cold spring and a summer heatwave.

Households made more than two million calls to water suppliers across England and Wales over the year to resolve problems, although this was almost 60,000 fewer than the year before.

CCWater chief executive Tony Smith said: "Far too many customers are having to waste their time and suffer the frustration of disputing unclear or inaccurate bills.

"In the autumn we'll be bringing the whole industry together to try and improve the standards of billing, as well as demanding a significant fall in the complaints made to the four poor performers named in our report."

South East Water remains one of the best performing water and sewage companies, while Anglian Water, South Staffs Water, Hartlepool Water and Wessex Water also earned praise for their performance.