If your furnace is producing warm air but you can’t seem to get the desired temperature, it could mean your thermostat is faulty. Try adjusting the temperature up and see if your system reacts. The temperature sensor could be malfunctioning, in which case you’ll want to call an HVAC service tech. Upgrading to a smart thermostat is one way to improve the efficiency of your heating system. Our service specialists test and calibrate your thermostats during an annual furnace tune-up.