Is the heating in your apartment not working as it should? If your apartment gets heat but it's erratic or unreliable and you can't figure out why, the culprit may be a faulty thermostat. If you suspect a problem with your thermostat, ask the landlord to check it out.
Your landlord, super, or the landlord's electrician should be able to diagnose and resolve a thermostat problem fairly promptly. The fix could be as simple as a careful cleaning of the inside of the thermostat (after making sure the circuit breaker is off), or it could require a realignment of the unit on the wall or a repositioning elsewhere on the wall or in your apartment. If your thermostat is very old, your landlord may need to replace it with a new model.