Hundreds of residents in Torbay, North Shore, were without hot water for much of the weekend.
Power company Vector spokeswoman Charlene White said extra crews were last night trying to restore hot water.
"There's some problem with the pilot wire that controls the hot water in the North Shore," she said.
"We thought we had repaired it this morning [Sunday] . . Our crews are patrolling it bit by bit to identify the problem."
A cold shower was an unexpected shock to Lara Miller, who lives on Awaruku Rd, after a Saturday afternoon netball game.
"It's pretty difficult ... We've been going to the mother-in-law's just to shower."