It is important to remember not to crowd floor heaters. If you place your furniture right up against the heater then the heat will be blocked from spreading into the room. This will lead to inefficiency and will probably cause you to turn the heat up higher and longer than you would need to otherwise. If it is unavoidable that you put furniture in front of a heater, be sure to leave space (maybe 6 inches minimum) between the wall and the furniture. You need to allow it to actually do its job, and that job is increasingly important during these chilly months.