1. Since the AUTO setting means the fan is only engaged when the system is on, rather than constantly blowing, AUTO is the most energy-efficient option between the two settings. This means you'll be using less energy and saving money on your electric bill by using the AUTO setting.
When it comes to whether you should set your furnace fan to “on” or to “auto” in winter, the answer for me is “auto” because it's the move that has the most to do with energy efficiency. It is not, however, the only thing you can do this winter to bolster your HVAC system's energy efficiency.
Higher Energy Efficiency — Using the “AUTO” setting helps increase energy efficiency by reducing the amount of energy used to keep your home comfortable. This means you're wasting less electricity and exposing your furnace system to less constant heating.
Lastly, while we do not recommend using “Auto” mode for the heating and cooling function, we do recommend using “Auto Fan” mode to control air circulation as it tends to be the most efficient setting for that function.
Which Thermostat Setting Is Best: On, Auto, or Circulate? Given the amount of money it costs in increased utility bills and filter purchases to keep your AC fan running constantly, most of the time, you'll want to keep the fan in the “auto” position.
"AUTO" is the more energy-efficient option, as it runs the fan only when heating or cooling is actively needed.
The heater might blow cold air rather than warm if the gas line supply has been turned off. This usually happens when something goes wrong with the heater, and it breaks. For example, maybe there was a problem with a gas valve, the gas supply pipe, or something else in your furnace broke down.
Keeping your fan on AUTO is the most energy-efficient option. The fan only runs when the system is on and not continuously. There is better dehumidification in your home during the summer months. When your fan is set to AUTO, moisture from cold cooling coils can drip and be drained outside.
During the winter months it is best to allow your heat pump to run at a lower fan setting and spread heat out more evenly over a longer period of time. The reason for this is two fold: Maintaining temperature over a longer period of time is more efficient than getting a room to temperature quickly.
The main benefit of setting the thermostat to 'Auto' is that it will result in more energy efficient usage. This is because the fan will run only when it's required. Also, the air filter will need to be changed or cleaned less frequently when the thermostat setting is set to 'Auto'.
Circulating the heat helps avoid having warmer or cooler spots throughout your home. Better Air Quality: Setting the fan to “on” also means the air will constantly cycle through your HVAC unit's filtration system. If the filter is changed regularly, fewer particulates will be in the air, further improving comfort.
The fundamental difference between the “auto” and “on” settings is that the fan runs continuously with the “on” setting, even if the heating unit shuts off. The “auto” function allows you to control how long the fan operates. Once the set interior temperature is reached, the unit and the fan stop.
A range of 68-70 is the best setting in winter if you want to save money because your furnace or heat pump doesn't have to work as hard as it does to reach a higher set temperature. The DOE says the smaller the difference is between the indoor and outdoor temperatures, the more you can save.
By some estimations, experts report that homeowners can save as much as 15% on heating costs when they run ceiling fans during the winter. Due to the improved distribution of heat in the room, thermostats can be turned down. When you do that, your heater runs less often, consuming less energy.
Auto: Fan runs only when the heating or cooling system is on. On: Fan is always on. Circ: Fan runs randomly about 33% of the time. *The circulate option that allows you to set the fan to run a certain amount of time per hour.
Check the Furnace's Power Switch
If the circuit breaker is functioning correctly, inspect the on/off switch for the furnace. This switch looks like a typical light switch and is usually located directly above the furnace or on a nearby wall.
It's natural to think "AUTO" mode would be a more efficient setting. But if you use it, your unit runs the risk of toggling unnecessarily between heating and cooling. Your heat pump will run most efficiently when set to "HEAT" in winter and "COOL" in summer.
Avoid “Auto” mode.
To avoid accidentally air conditioning on a mid-winter sunny day or perhaps when a wood stove is running, use “Heat” mode, not “Auto.” Likewise, to avoid accidentally heating on a cool summer night, use “Cool,” “Dry,” or “Fan” mode, not “Auto.”
During summer months, your ceiling fan blades should be set to spin counterclockwise. When your ceiling fan spins quickly in this direction, it pushes air down and creates a cool breeze.
Using the “Auto” Setting
This setting offers benefits including: Increased energy efficiency by running the fan only when needed. Extended filter life as the fan operates less frequently. Lower energy bills due to reduced electricity usage.
Since the AUTO setting means the fan is only engaged when the system is on, rather than constantly blowing, AUTO is the most energy-efficient option between the two settings. This means you'll be using less energy and saving money on your electric bill by using the AUTO setting.
If the heat is running and your house has oddly cold rooms, they are unevenly heated, or vents or radiators aren't giving off much heat – there could be a problem with heat delivery. Insulating your home will surely help keep the heat inside, but it first needs to be properly delivered.
Typically, there's a 10 to 15 minutes allowance for this. However, if after this time it's still producing cold air, then there's an underlying problem that needs to be addressed. It would be wise to turn the furnace off and get in touch with a pro immediately for help dealing with the issue.
If your HVAC system isn't blowing warm air, start by checking the thermostat settings and batteries; more complex issues like faulty wiring or ignition system problems may necessitate professional assistance. Airflow restriction due to clogged air filters can result in your system blowing cold air.