It's the heating season when furnaces run. But should the thermostat be set fan "auto" or "on"? It's an age-old question with no right or wrong answer. It just depends on what you'd like done. When the thermostat is set to "auto," the fan operates only when the temperature drops and requires the furnace to run. This is the most-used setting, as it saves both electricity and fan wear and tear. However there are advantages to using the "on" setting and there are times when "continual" operation is desirable. When the thermostat is set to "on," household air is constantly circulated and cleaned by the furnace air filter. Another benefit of constant circulation is that it results in a more even temperature throughout your house. This helps to eliminate potential cold spots and possibly having your furnace running even more than it should. What's best? It depends -- either one can be good. And that's the On The House tip for today.