The fan will run and blow warm air but only in FAN or FAN ON mode – delivering heat – but NOT in AUTO mode. This is a bad temperature sensor in the unit; replace the fan limit controller.

Does the HVAC fan run when heat is on?

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.

Should fan be on AUTO or on for heat?

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.

What would cause a furnace blower not to kick on?

Make sure that the power cord hasn’t melted or a fuse hasn’t been blown. If your cables are looking fine, try unplugging the fan for a few minutes and then plugging it back in again. Sometimes, this process can reset the motor and solve your furnace problems.

What device turns on a blower motor during the heating mode?

The high limit switch is also an extremely important safety device inside your furnace. When the furnace begins running, the switch’s role is to turn on the blower fan when the supply air gets hot enough.

Is it OK to run HVAC fan continuously in winter?

Reduced Wear & Tear

Furnace fans are designed to run all the time, so there’s no need to worry about it failing prematurely. Much of a furnace fan’s wear and tear comes from the starts and stops of the motor; keeping it running can eliminate this type of stress.

Is it OK to run HVAC fan continuously?

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.

Is it OK to leave furnace fan on all the time?

As previously mentioned, newer models of furnace systems include fans that are designed to run continuously. Assuming that your heating equipment was properly installed by a professional and has correctly-sized ductwork, letting the fan run continuously may actually help extend its service life.

Why will a blower run on the on position and not on AUTO?

That’s because if the heater never warms up then the fan controller won’t automagically turn on the blower fan. Let me know what you find. Electric split unit trane the fan comes on in the on position but not in automatic. Heat or cool isn’t working on the condenser or evaporator .

What’s the difference between fan and AUTO on thermostat?

The fan setting controls your AC’s blower; A fan inside your system that helps distribute air throughout your home. AUTO means the fan turns on “automatically” ONLY when your system is heating or cooling your air. When the thermostat reaches your temperature setting, the system, including the blower fan, shuts off.

How do you reset a fan limit switch?

Quote from the video:
Quote from Youtube video: Control normally will not reset itself so in the case where that limit is open it has a manual reset on it basically you have to push the little button down on top of the on top of the limit control.

How do I know if my fan limit switch is bad?

The most common sign of a malfunctioning limit switch is the continuous operation of your furnace’s blower. Just as the limit switch won’t allow the fan to turn on until the warm air has reached the right temperature, the limit switch also shuts down when the air cools to a certain temperature.

Where is the furnace fan limit switch located?

Your fan limit switch is located inside the furnace panel cover, usually near the upper right corner. The fan limit switch is responsible for turning the blower on and off at the appropriate times.

How long should my HVAC fan run per hour in winter?

Most systems should run about 2-3 cycles per hour. How long should the furnace or AC run in a given cycle? Typically 10-15 minutes in mild weather. The closer you get to the max design temperature in heating (0 Degrees) or cooling (90 Degrees) the longer the run cycle will be.

Why is my heat blowing cold air?

If your furnace is blowing cold air in your home, this is a sign of an issue with the flame detector, gas supply, air filter, pilot light, or condensate lines. Many of these issues are able to be easily solved on your own by sanitizing or replacing components in the gas furnace.

Does running your furnace fan continuously save energy?

Running your furnace fan all the time could save you money each month because having more even temperatures in the home results in the heat or air conditioner running less. Since the fan uses much less power than the outdoor unit, you save money in the end.

Is it expensive to run the furnace fan?

Higher Energy Costs

A standard furnace fan motor uses about 400 watts of electricity every hour. Assuming a national average of 12 cents per kilowatt-hour, let’s see how much that would cost you in the long run. If you run your furnace fan twenty-four hours a day, it will cost you a little more than $1.15 every day.

How often should you run your HVAC fan?

Pros to Running Fan on Air Conditioner Continuously:

Less frequent starts and stops of the fan can reduce the stress from startup, and potentially help extend it’s lifespan. Leaving the fan on 24/7 ensures cleaner air, as the air is pulled through the filtration or UV light system.