I have a Bryant Legacy plus 90 furnace that is about 2 & 1/2 years old. The furnace will kick on and run till the temp on the thermostat is reached, it then shuts down but will immediately start back up again and continue to cycle like this 5 or 6 times until I adjust the thermostat down a degree or 2. When the furnace kicks back on it will do the same thing all over again. Could this be a faulty thermostat?? Help!!