NI Water: History of problems for state-owned company
This is not the first time that NI Water has been in the firing line from angry customers.
In late 2010 some 450,000 people were left without supply after freezing weather caused chaos.
More than 40,000 homes were off mains supply and, at the height of the crisis, one million people tried to ring NI Water.
Some were left without water for more than a week.
NI Water chief executive Laurence MacKenzie resigned in the wake of the crisis.
Many were critical of the state-owned company's failure to come to the aid of those in need.
In November 2011 thousands of customers in Ballymoney had to boil their water because of problems with the supply.
And in 2013 a water pressure problem caused severe trouble in Ardglass. Homeowners were left with bills running into thousands of pounds after water pipes burst, hot tanks cracked and shower fittings were blown off walls.
Current NI Water chief executive Sara Venning joined in April 2010 and according to NI Water's latest annual report she receives between £130,000 and £135,000 a year in salary and allowances, plus pension benefits of £51,000.