Pepco Energy Services, which owns a power plant that provides cold water to Trump Plaza Hotel and Caesars Atlantic City to power their cooling systems, said the restoration was completed at both sites Sunday morning.
That came about one day after operations had restarted.
Temporary systems at both casinos were operating Sunday at full capacity, and Pepco officials say temperatures were at or near "standard operating conditions" at both sites. Meanwhile, work to restore air conditioning at Boardwalk Hall, a concert venue temporarily shuttered by the cooling problems, continued Sunday.
The cooling problems were caused by a leaky underground pipe at the plant, which is being excavated. It's not yet known what caused the rupture or when the repairs will be completed, and temporary systems are being used to cool affected venues.
Trump Plaza - which has been shut down since Friday - planned to reopen its casino at 4 p.m. Sunday, but guests won't be able to get to their rooms until 6 p.m.
The closing is expected to cost Trump Plaza several million dollars. And though Caesars Atlantic City has remained open, crowds there have been sparse.
It is extremely rare for an Atlantic City casino to close down temporarily.
Aside from the three-day state government shutdown in 2006, the only other time in recent history that casinos shut down briefly was when Hurricane Gloria moved up the East Coast in September 1985, according to Dan Heneghan, a spokesman for the state Casino Control Commission. The storm eventually veered harmlessly out to sea.
In the 1980s, Caesars was shut down for one day as a penalty for regulatory violations, Heneghan added.