Our furnace was recently replaced with one with a much higher efficiency. That whole process was handled well and we were satisfied. However, there was one exception. During the decision making process it was overlooked that for the new furnace actually performs as advertised ONLY if an upgraded thermostat is also installed. Sure enough, the furnace did not seem to be functioning too well and the cause was traced to the incorrect thermostat. Slight frustration and a bit of additional expense to replace the thermostat. Now working great and highly recommended.
