Heat Pump Contactor Replacement

Heat Pump Contactor Replacement Video Transcript

Do you need a heat pump contactor replacement? In this video, Casey Services will show you bad contactor symptoms,
[On screen: In this video:]
[On screen: Bad contactor symptoms]

why it may fail,
[On screen: Why it may fail]

the steps in a replacement,
[On screen: Steps in a contactor replacement]

as well as the cost of parts and labor.
[On screen: Cost of parts & labor]

If you want to watch our full Heat Pump repair series, where we cover the major repairs, their symptoms, and costs, then follow the link.

A heat pump contactor replacement keeps power flowing to all other parts of your heat pump system. Without a functioning contactor, your heat pump just won’t work properly. If you live in Raleigh, Wake Forest, Durham, or the surrounding areas, Casey Services HVAC can troubleshoot and replace your heat pump contactor!

Signs of a Bad Heat Pump Contactor

There are several signs that your heat pump contactor might be bad.
[On screen: Bad heat pump contactor]

Your contactor not pulling in,
[On screen: Not pulling in]

failing to turn on or off,
[On screen: Won’t turn on/off]

buzzing noises,
[On screen: Buzzing noises]

short cycling,
[On screen: Short cycling]

or severe corrosion can mean it’s time for a replacement.
[On screen: Corrosion]

Why Did My Heat Pump Contactor Fail?

The most common causes for contactor failure are extreme voltage,
[On screen: Common causes]
[On screen: Extreme voltage]

environmental debris,
[On screen: Envir. debris]

bad coils,
[On screen: Bad coils]

water damage,
[On screen: Water damage]

or loose electrical connections.
[On screen: Loose elec. connections]

You’ll need a tech to do the heat pump contactor troubleshooting.

Cost of Heat Pump Contactor Replacement

A new heat pump contactor costs anywhere from $20 to $100 depending on the brand and year of your heat pump unit.
[On screen: Replacement cost]
[On screen: Contactor: $20-$100]

The average contactor replacement is $75-$100 an hour,
[On screen: Labor: $75-$150/hr]

and the job takes about 1-2 hours.
[On screen: 1-2 hours]

Learn more by checking out our Heat Pump Repair Cost Series.

Don’t Get Scammed

Some companies try to scam you on a heat pump contactor replacement. When in doubt, ask the tech for the diagnostic report, and take pictures of the damaged contactor and the new one.
To learn more, check out our series on how to avoid Heat Pump scams.

Replacement Process

Each brand and year of heat pump is slightly different, so the process will vary. The general steps that a reputable HVAC technician like ours should take when doing a contactor replacement is:
[On screen: Replacement process]

First, your HVAC tech will turn off the high and low voltage. Be sure he turns off power to both the outdoor and indoor units.
[On screen: Turn the power off]

Next, the tech will remove the exterior panel and identify the contactor. Typically, it’s on the top right side.
[On screen: Remove the panel]

Following this, your tech should unscrew the contactor and detach wires connected to it.
[On screen: Remove the contactor]

The tech will then reverse the removal process and attach the new contactor.
[On screen: Attach new contactor]

Once attached, your tech will turn on the power to your heat pump system to test the new contactor.
[On screen: Test the contactor]

If you want to learn how to test a contactor, then check out our series.
Lastly, your tech will reattach the exterior panel.
[On screen: Reattach panel]

Always have a licensed tech work on your heat pump contactor replacement. This keeps you safe, and is usually required for your warranties and home insurance
Save money and stay comfortable – learn more with Casey Services.


Heat pump contactor replacement can be a simple and quick job for an experienced technician. The contactor’s job is to keep power flowing to all other parts of your heat pump system. Without it, your heat pump can’t effectively or efficiently heat and cool your home. Below we review some signs & symptoms and go over the expected costs if you’re looking to get a contactor replacement for your heat pump in the Raleigh, Durham, or Wake Forest areas.

Signs of a Bad Heat Pump Contactor

Two heat pump technicians work to diagnose a unit

If you feel like your system is acting abnormally, then you may need heat pump contactor replacement. Your contactor is a small magnetic switch located in your outdoor condenser unit. When engaged, it completes the electrical circuit to turn the unit on. A bad contactor won’t – or won’t stop – relaying power to the unit, so your heat pump can’t effectively or efficiently move heat energy into or out of your home. Here are a few symptoms of a bad heat pump contactor:

  • Fails to turn on or off correctly – If your heat pump is not powering on and off reliably, whether you’re cooling or heating, a bad contactor could be the culprit.
  • Contactor buzzing – Faulty contactors can cause your heat pump to make a buzzing or humming noise when attempting to start or stop.
  • Short cycling – If the contactor is not making a good connection, it causes the heat pump to turn on and off rapidly; this is called short cycling. This is a common symptom of a fault contactor.
  • Visible damage – A melted contactor casing or corroded contacts means it’s time for a replacement.

These are some of the most common symptoms. You may be experiencing others, and if you are, it’s best to reach out to us to properly diagnose the system.

Why Did My Heat Pump Contactor Fail?

A contactor is an integral part of your heat pump system and there are many reasons why it might fail. Before you start to DIY it and troubleshoot it on your own, you should know that DIY fixes can result in injury, a voided system warranty, or even loss of insurance. So before you jump into troubleshooting mode, let the professionals examine it first. Here are a few likely causes they might find:

  • Power Surge – Too much voltage can overheat a contactor. This leads to “pitting” of the contactor, which causes the unit to continually stay on.
  • Environmental debris – Over time, dirt, leaves, dust, and even bugs & animals can get stuck between the contacts, causing a disruption in the flow of electricity. Ants in particular are drawn to electricity and can gum up the works.
  • Bad coils – Within the contactor there is a coil, which is wrapped around an electromagnetic core. The charge and magnetism of this component are what pull down the plunger of the contactor, which is what completes the electrical circuit of the whole unit. When the coils fail, it’s time to replace the contactor.
  • Water damage – If water is present when your contactor is powered, the coil will likely short. To see if this is the case, the tech will measure both sides of the coil using a tool like a multimeter. If the multimeter reads OL, it means the coil is burnt out.
  • Loose electrical connection – Any corroded electrical connections at the spade terminal could cause low voltage on your contactor coil, which means your contactor will not be engaged. You need between 24 and 29.5 volts to make the contactor work. Anything lower is not sufficient and could burn out the coil.

While these are some of the most common reasons a contactor might fail, there are others. But, to be 100% sure, it’s best to hire a professional to diagnose the problem. Heat pump experts have the right tools to identify the issue accurately.

Cost to Replace a Heat Pump Contactor

There are two things to consider: replacement parts and labor. These costs are primarily focused on the Raleigh, Durham, & Wake Forest areas.
The graph below shows how much the cost of the part has varied over the last few years. To learn more about why the price has varied so drastically, check out our blog on the HVAC parts shortage.

How Much Does a New Heat Pump Contactor Cost?

A new contactor costs anywhere from $20 to $100 on the high side, depending on the brand and year of your unit.

click to enlarge

Note: You’re likely to find a part on the internet pretty cheap. However, most HVAC companies purchase parts that have special warranties that both follow their systems manufacturers’ guidelines and cover more than what the average homeowner can buy. Also, many heat pump repair companies will not install parts they didn’t purchase due to the risks of it being defective.

Labor Cost to Do a Heat Pump Contactor Replacement

The average labor cost is between $75-$150 an hour. And the job can take around 1-2 hours.

This rate might seem high, but keep in mind that these rates include the cost of the expertise, certifications, and insurance of the technician, as well as their time. This ensures the job is done well and you’re covered in worst-case scenarios.

Am I Being Scammed?

Often, when you’re asking for help in an area where you don’t have experience, it can feel like you’re vulnerable to those who could take advantage. These are some tips you can use to make sure the company you’ve hired is on the up and up.

  • “Show me” – Ask the technician to show you the damaged contactor. Looking at the new and old contactors, you should be able to see a difference – bad contactors are often burnt or discolored thanks to the oxidization of the metal. Be careful, though. Sometimes the contactor will look discolored but function fine. That’s why it is important to check the amperage.
  • Correct Amperage – Ask them if the contactor is pulling in and pushing out proper amperage based on the manufacturer’s specifications. You can look this up if you know the unit number, which is typically listed on the side of your outdoor unit.
  • Double-check electrical – Ask the tech if all electrical components are tight, as loose bolts and wires can cause a short or blown fuse, resulting in a lack of power.

How to Replace a Heat Pump Contactor

As expert heat pump technicians, we don’t recommend you do this on your own unless you are fully licensed and insured. But here are the steps you can expect the tech to perform while they are working on your system:

  1. Turn off the unit – The first step is to turn off the high and low voltage. This prevents damage to the system AND the technician. Be sure to turn off power to both the outdoor and indoor units.
  2. Remove the exterior panel – Next, remove the exterior panel on the right side of the unit and identify the contactor, which is typically on the top right of the panel.
  3. Remove the contactor – Your technician should then unscrew the contactor from the interior of the unit and detach the wires connected to it.
  4. Attach the new contactor – Reverse the removal process and attach the new contactor.
  5. Test the contactor – After reattaching the contactor, your technician will turn on the power to the system to test the contactor to make sure it is functioning properly.
  6. Reattach exterior panel – With the new contactor up and running, reinstall the exterior panel. Now the replacement is complete.


For most skilled technicians, heat pump contactor replacement should be a straightforward and easy replacement. While there can be many causes of a failed contactor, power surges, water damage, etc., at Casey Services, our skilled techs are able to diagnose it and get your system working again.

Casey Services HVAC Inc

Need help?

  • This field is for validation purposes and should be left unchanged.