Heater problems

Our heater has been having trouble since last winter. We had to manually control the temperature by turning off the heater when it got too hot and turning it on when it was too cold. The thermostat never kept an even room temperature. This did a number on our power bill, as you can imagine (no pun intended :). Well, our landlord finally came out to look at it and replaced it while he was here and it seemed to click on and off at the correct place so we hoped it was fixed. Well, a half hour after he left we realized that the heater was not on even though the thermostat had clicked on. Tim fiddled around with it to no avail. So we don't have a heater in the living room anymore and that's our main heater! :( We have another message into the landlord so hopefully they are able to come out again right away. We aren't freezing though because we've got heaters in the bedrooms and a small spaceheater to use out here. It's just frustrating, especially when it's messing with our power bill.