Your HVAC fan should turn on and off with the rest of your heating and cooling system. It’s normal for the fan to kick on a couple of minutes before heating starts or to stay on for a couple of minutes after cooling stops, but your fan shouldn’t run for hours on its own.
Why does the furnace fan run when the heat is off?
If your fan limit switch is set to AUTO but the fan continues to run without ever stopping, you’ll need to call a professional. Two problems that could cause your fan to run without stopping include: A bad fan limit switch that needs to be replaced. Bad thermostat wiring.
How long should furnace fan run after heat shuts off?
Typically, because the oil or gas burner is NOT running (because the thermostat is not calling for heat), the blower fan should not run more than a minute or two before stopping.
Why does my furnace blower not shut off?
On your thermostat, look for the fan settings. There should be two, “ON” and “AUTO.” If it seems like your furnace won’t turn off, the thermostat may be set to “ON” for the blower. Toggle the switch to “AUTO” so your furnace’s blower fan only runs during a heat cycle.
Should my furnace fan be AUTO circulating?
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.
Why does my blower fan keep running?
Faulty Thermostat: If both the fan and either the cooling or heating system are running unexpectedly, you may have a faulty thermostat. Broken Relay Switch or Short Circuit: If only the fan is running, there may be a broken relay switch preventing the settings you enter on the thermostat from being sent to the fan.
Why does my furnace make a noise when it shuts off?
This backup of heat causes the metal of your ducts and the furnace itself to expand and bow outward. Once the heating cycle stops, the sheet metal of the ductwork and the metal panels of your furnace cool and contract, producing a ‘bang’ or ‘pop’ that you hear inside your home.
Is it better to leave furnace fan on or AUTO?
“auto” is the best setting for your furnace fan in the winter. It will aid in saving energy and money while also working to keep your home at an optimal temperature. However, for summer, “on” is the best setting for your furnace fan.
Should I leave my furnace fan on in winter?
It also extends the life of your furnace air filter and blower, which can keep repair bills down. During the winter, setting your furnace’s fan on can result in circulating more unwarmed air, so it is not usually recommended.
Should fan be on AUTO or on for heat in winter?
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.
Should blower run constantly?
Better Indoor Air Quality
Whenever the fan is on, air is going through the furnace filter. Leave it on continuously and you’re likely to see less dust around. It’s also important to have a good filter. The many types of HVAC filters can help reduce allergies, VOCs, as well as bacteria and viruses.
Why does my gas furnace fan keep running?
The fan control should be set to AUTO. You can try turning the switch to OFF too. Other snafus such as a shorted thermostat wire can also cause the A/C or warm air furnace fan to run continuously. at THERMOSTAT WON’T TURN OFF.
Why is my fan running when my thermostat is off?
If the fan is the only thing running when the AC unit isn’t, there may be a faulty relay switch prohibiting the settings on the thermostat from being communicated to the fan. Another cause could be a wiring issue or a short circuit preventing the system from recognizing the on and off signals.
