I recently moved into a new house with several wall-mounted heat pumps. I've never used these heaters before but I sat down and read the manual (all 9 pages of it...) and thought I had it figured out. Set the pump in the bedroom to 66 and went to bed. Woke up this morning and it was 81 degrees in there. Outside temp was 35. Any ideas what I did wrong? Do these pumps not shut off when the room gets up to temperature?