We reported the heater was not working to the property managers on duty at about 8:00 pm on our first night. It wasn't repaired until about 2:00 pm the next afternoon. The problem was an incorrectly installed thermostat which caused a wire in the wall to short and burn through the it's insulation.
Neither we nor, apparently, the property managers were aware of a 25 hour emergency line. There were two small, noisy space heaters in the unit which we chose not to run continuously overnight. After a cold night, we discovered that we couldn't run both space heaters and any other appliances, including a laptop, at the same time because the unit was wired with only one circuit and the breaker would trip. The breaker was located at the other end of the building in a locked room. Preparing breakfast with a microwave and toaster oven while trying to heat the place took quite awhile.
When we followed up with the owner about the problem (She hadn't been notified of it.) and asked for a one night refund, we were chastised for not using the 24 hour line, not running the space heaters all night, and not contacting her while we were there. She also said there had been intermittent problems with the heater in the past, but thought they were resolved. We were refunded approximately one half of one night's rental charge.
As always, Caveat Emptor, but we hope our experience will lead to an inspection of all electrical work the contractor who installed the thermostat did on any other thermostats and heaters in any of the units.