As cold weather approaches, building owners are required by the city's Department of Housing Preservation and Development to turn up the heat.
The heat must be turned on from 6 a.m. to 10 p.m. between October and May.
Mechanics say homeowners and landlords should check the gauges on their water boilers to make sure everything looks OK. Problems can lead to frozen pipes, which can then burst and cause flood damage.
Experts say that residents should call 311 to report issues, because larger problems can occur when people try to fix heating systems on their own.