Debbie Walls says a heater broke in late December in one of the two hot water tanks that supplied the 133 residents of Mount Saint Joseph Nursing Home in Miramichi.
She says the home installed a temporary water heater, but it wasn't compatible with the circulation pumps serving the four-storey building.
Walls says as a result, staff and residents have had to run taps for as long as 20 minutes to get hot water.
She says the privately-owned, publicly-funded home is receiving help from the province to install a new heater with a compatible pump.
Nichole Bowman, a spokeswoman for the provincial Department of Social Development, says it has provided funding for the home to hire a mechanical consultant.
Neither Wall nor Bowman could say specifically when the system will be fixed, though Wall said there are no health or safety concerns as a result of the lack of hot water.