Keep hot appliances away from the thermostat

Don't put appliances that generate heat, like lamps and TV sets, under your wall-mounted cooling thermostat. The heat rising from them can cause the thermostat to read a temperature that's higher than the actual room temperature and lead to overcooling the whole house...

The same holds true for thermostats that are placed under a vent. It may be a bit of effort to relocate the thermostat, but you'll save money, and likely be more comfortable anyway.