Heating & Cooling

Which Way Does a Heat Pump Fan Turn? (Explained)

Heat Pump 2 Lg

Heat pumps are excellent when it comes to heating and cooling your household. Not only are you saving a massive amount of money, but it is less maintenance overall. 

In order for the condenser to work properly the fan has to turn correctly. However, an outside fan can be turning correctly yet give you the illusion that it’s not.

The outdoor heat pump condensing fan turns in a clockwise motion, regardless of the mode it is in. The fan blade spins so fast, it can create an optical illusion that the fan blade is spinning backward when it’s not.

Heat pump condensing fans, even in dual-fuel setups, should never be covered because the condensing fan will still operate as part of the heating cycle.

In an air conditioner with a gas furnace, the condensing fan spins clockwise in the cooling mode but doesn’t operate in heat mode. It’s common for people to cover their air conditioners in the offseason in cold climates.

You can verify the fan is spinning clockwise because the fan draws in the air across the coil and blow air out the top.

Let us delve into which way a heat pump should spin and uncover why it might have stopped spinning or turned off in the first place.

Which Way Should a Heat Pump Fan Spin?

You turn on your heat pump and notice that the fan starts spinning clockwise, then it looks as if it automatically turns counterclockwise. Once you turn the device off, you can easily see it is spinning in one specific direction.

In that case, it is much easier to think that your device is broken instead of thinking your eyes are deceiving you. 

You need to know that when the fan starts spinning quickly, it looks as if it is going in one direction but is it not.  

Does a Heat Pump Fan Change Direction?

You are outside working in the backyard and want to quickly check your heat pump to see if it is okay. Low and behold, you noticed that the fan appears to be spinning in the wrong direction.

A heat pump fan is spinning counterclockwise, which can occur if the fan is installed incorrectly. Otherwise, the fan will only turn in one direction or not turn at all.

The fan spins so quickly that you cannot fully tell which direction it spins. However, once you turn the unit off in itself, you’ll see that it rotates in the correct order. 

You cannot tell which direction it goes unless you slow it down or follow the blades with your eyes for multiple seconds.

Does the Heat Pump Fan Spin When the Heat is On?

A heat pump system has a few essential parts that work hand-in-hand that you should keep in mind: it has an outside unit and an air handler unit inside your home. If no air comes out of the outdoor unit or air handling unit, it is off. 

When a heat pump is running, the outdoor unit will also run. There is sometimes a 5-minute delay when switching from heat to cool and vice versa. The heat pump uses a reversing valve to control the refrigerant flow between heat and cool modes. The outdoor fan can stop during this change order or during a defrost cycle.

In a dual fuel heat pump, the process is the same. The gas furnace is a backup for extreme cold or when you need to heat your home rapidly.

Will an Air Conditioner Operate When the Heat is On?

Air conditioners are similar to heat pumps yet also different in many ways. Air conditioners are paired with an electric or, more often a gas furnace. Air conditioners do not have a reversing valve that reverses the flow of refrigerant.

The air conditioner fan turns clockwise in cooling mode. However, in heating mode, unlike a dual fuel heat pump, the air conditioner is not used. Gas furnaces are systems that can heat without the use of an outdoor unit. Many homes, still have a furnace and no air conditioner.

When Should the Heat Pump Fan Turn On?

If no air enters within the heat pump fan, your automatic response will be wondering why it is not working. The heat pump fan should start turning when the house needs to be heated. 

In other words, if the house’s temperature does not match the thermostat, then the fan needs to turn on to regulate the temperature. 

Have you ever had an outdoor fan that refuses to turn on? Have you ever had to “push start” the fan manually until it finally works again? You then do not want to turn it off again for fear of doing the same process once more. You likely have a weak fan motor or capacitor.

The same thing happens to a heat pump fan as well. Over time, the fan motor will not be as strong as it should be, which means it needs a push to turn on. 

If you are experiencing this issue, it is a prime indicator that you’ll need to replace the fan motor altogether to stop this issue. 

It may be wise to call a qualified HVAC technician help unless you have experience with these sorts of things. 

Note: Do not use the heat pump until the issue gets resolved. It can cause immense damage to the compressor, which can be expensive, and you will have to replace the entire system at this point. 

Should a Heat Pump System Run During Cold Weather?

It might seem odd that the heat pump fan runs during the winter, primarily when the air conditioning unit does not run during these times. 

However, it is entirely normal for the heat pump system to run in the colder months throughout the year. 

In freezing temperatures, a heat pump is not ideal because of how much harder it works to bring more air inside your home. 

This work on the heat pump makes it much harder to get the air inside, making the entire unit much less effective than a typical furnace. 

Some homeowners opt to have a backup heating system for the winter instead of the heat pump for this issue.  

On the other hand, if your fan continuously spins and does not stop, that could mean one or two malfunctions:

  • In the air handler
  • In the blower

The heat pump fan can defrost the unit in itself as well. If the air handler and heat pump continuously work, but the fan does not spin, this indicates a more significant issue even when the weather is cold. 

How Often Should a Heat Pump Cycle On & Off?

When it comes to your home, you will always want to watch all of your appliances, and a device outside is no exception. 

A moderate heat pump should cycle between 10 to 20 minutes per cycle and 2 to 3 times per hour. 

However, this depends on the room temperature, humidity, and the unit’s cooling capacity, so keep that in mind. 

If the heat pump runs a relatively short cycle by any chance, then odds are, it is not working correctly. 

We will delve more into that down below, but firstly, it is essential to know that your heat pump should not constantly be running unless the weather is freezing or below 35 degrees. 

Following that, if the heat pump is short-cycling above the temperature mentioned, then it is safe to say that something is wrong with it, and a professional should come and look at it.

How Do I Know if My Heat Pump is not Working Properly?

There are many ways you can find out if your heat pump is not working correctly. Of course, you will want to have this information on-hand if something occurs. 

1. Your Air Filter is Clogged

Sometimes, solving an issue might be as easy as unclogging your air filter. Some devices might be washable, while others may change out frequently. 

Just like how you need to regularly change the air filter in your regular air conditioning system (if you have one), the same thing goes for switching out a heat pump filter. 

Dust and debris are always issues for fans, AC units, and heat pumps. 

If this issue is not taken care of often, other issues might arise, such as frozen evaporated coils or constantly turning off and on. 

2. You May Have an Oversized or Undersized Unit

Do you feel your living space is getting cooled or heated too quickly or less frequently than it should? If that is the case, the unit itself may be too large or small. 

The unit will shut down quicker than usual and begin to overwork itself in the long run. Overall, your heat pump will break much faster than it would if your home met the proper size of the unit. 

A rule of thumb is that your home needs 30 BTU per square foot with a standard ceiling of 8 feet tall. 

Here, we have put a chart together to help you determine what size BTU your heat pump should have (based on a home that has an 8-foot ceiling height):

Home area (sq. ft.)BTU needed
600 sq. ft.18,000
800 sq. ft.24,000
1000 sq. ft.30,000
1200 sq. ft.36,000
1600 sq. ft.48,000
2000 sq. ft. 60,000
2500 sq. ft.75,000

3. The Refrigerant is Leaking

During summertime, the refrigerant of your heat pump takes the heat outside. However, when cold enters your home during winter, heat is taken from outside and penetrates in a pressurized manner. When your heat pump leaks, then this process is tough to do. 

If you see ice on your outdoor unit, odds are the thermostat is having some issues, which means the device will not complete an entire cycle of being on and will shut down. In that case, it is essential to call a professional to help out. 

4. There Might be a Thermostat Error

If you place the thermostat near a window, vent, or somewhere that is drafty, then it may be reading the temperature wrong, meaning it is causing inaccurate readings.

The thermostat’s wiring also might be out of place or even faulty so you will need a professional’s help with this particular issue.

If the thermostat does not get to where it needs to be, it is short cycling. 

Short cycling is where your system shuts down earlier than usual because it cannot complete the heating and cooling system at bay. 

Why is My Heat Pump Blowing Cold Air When the Heat is On?

There are a couple of reasons why your heat pump is blowing cold air when the heat is on:

1. It is in Defrost Mode

Manually removing ice is extremely difficult, time-consuming, and hard to manage, especially in frigid weather. Regardless, having an automatic defrost mode is an excellent idea for machines and devices. 

One might mistake the defrost mode with the cooling mode because of their similarity. It is more than likely that colder air blows in the defrost mode. 

Because many heat pumps are like air conditioners in reverse, meaning that an average air conditioning cycle generates cool and warm air in different stages of condensation and compression. 

It is possible to switch a heat pump into defrost mode. The heat gets released through the indoor unit, making the ice melt. 

Note: Make sure the defrost cycle finishes before switching it back to normal. 

2. There Might be Something Wrong with the Unit

One of the many ways you can tell if your system is not working is if the pump blows cold air instead of heat. There can be a few reasons for this:

  • Faulty reversing valves (which require a lot of time from an HVAC professional)
  • Leaking refrigerant lines

Final Thoughts

For our final words in this article, a heat pump fan turns clockwise, regardless of the mode you place it in.

Another thing to consider is that if the fan blows clockwise and you turn it in, you might be seeing that it spins the other direction. Yet as you turn off the motor, you’ll know that it rotates clockwise. 

In this case, the fan spins so quickly that you cannot fully tell which direction it turns, just like a ceiling fan or small fan within your home. 



Hubert Miles | Licensed Home Inspector, CMI, CPI

Hubert Miles is a licensed home inspector (RBI# 2556) with more than two decades of experience in inspection and construction. Since 2008, he has been serving South Carolina through his company, Patriot Home Inspections LLC. As a Certified Master Inspector, Hubert is dedicated to providing his expertise in home inspections, repairs, maintenance, and DIY projects.