In a survey of 250 businesses, the national register of approved contractors found the healthcare sector was most at risk of poor plumbing, with 50% of survey respondents reporting a botch job – compared to the national average of 31%.

The leisure sector follows this at 46% and financial services at 40%.

The most common reasons given for hiring a second tradesperson were:

• Wrongly-connected pipework – 46%
• The first contractor didn’t solve the problem they were hired to fix – 33%
• It caused a water leak – 29%
• The water didn’t smell or taste right – 28%.

When it comes to using an approved plumber, 88% of respondents say they would be more likely to trust a plumber on a register promoted by their local water company and 75% were more likely to trust a WaterSafe-approved contractor.

However, only 30% say they only ever use an approved contractor.

Julie Spinks, Director at WaterSafe, said: “It’s alarming to hear almost a third of people interviewed said the rogue installer they employed did not carry out the work properly. It gives reputable, qualified plumbers a bad name.

“However, our research shows that having the WaterSafe badge of approval does make installers appear more trustworthy, and for good reason, as it demonstrates they are qualified, belong to an approved contractors’ scheme, and carry Public Liability Insurance.”

The WaterSafe register is promoted by all UK water companies and drinking water regulators and was set up to help keep the UK’s drinking water safe in homes and businesses.

WaterSafe-approved plumbers are all trained to meet the strict regulations for installing pipes and fittings that supply drinking water. They will issue a Certificate of Compliance, stating their plumbing work complies with the regulations – giving customers a legal defence if something is later found to be wrong.

Membership also allows contractors to self-notify certain types of work to the local water supplier and access free advice on the water regulations.