[Voicer]

There is a separate switch to turn the furnace fan on to circulate air when needed. When turned off, the thermostat does not function. When turned on and the thermostat turned up, the burner ignites and the fan increases in speed. Turning the 'fan off' on the thermostat reduces the fan to a lower speed but the only way to turn it off completely is by the main switch. Is it normal for the fan the run constantly like this? If not, how do I control it from the thermostat?