My girlfriend thinks she has a problem with her heater in her apartment. It continues to run sometimes at a period as long as 2 hours without stopping. Then it will blow out cold air for about 10 minutes. It will shutoff for about 20 minutes then start back up. But it never gets to the disired temperature on her thermostat. She has it looked at twice by maintenance. They say it is fine.

Last night I was at her place, turned the thermostat up from 69 to 75. It ran for about an hour and a half till it got to about 72. Then it shut off. Then 2 hours later after it fell to 66 degrees, it turned on arounf 9 pm blowing cold air for about 10 minutes, then started blowing luke warm air, till about 1 am before we finally just turned the thermostat down. This can't be normal. She is worried she is going to have a high electric bill because it runs all the time. Can any provide any help or information?

It does not sound that it is working correctly. It should be checked by a on site professional HVAC mechanic or call the land lord.

Ok, well she has called the rental office twice and maintenance has come out twice changed the filter, cleaned the fan, and tested the system and has said it is working fine. But it still continues to do the same thing.

Unless you want to pay a local HVAC person to do a repair I guess you are stuck