Heat Pump Installation Process: What Your Technician Will Perform

Last year, there were about 190 million heat pump units in operation in buildings around the world. Heat pumps are great HVAC components for homes because they provide many benefits.

Heat pumps are efficient, safe, and can make your home’s rooms comfortable. However, to reap the advantages, you need to hire a professional heat pump installer.

What can you expect your technician to perform on heat pump installation day? Keep reading for a walkthrough of the process.

The Buying Process

Before heat pump installation day, you will talk to an HVAC sales representative about buying a new heat pump.

A technician should perform a Manual J Load Calculation to figure out the right sized equipment for your home. This formula may also be called an HVAC load calculation.

To come up with the size of equipment you need, installers and technicians will take a series of measurements into account. These measurements come from different parameters around your home.

This calculation involves more than calculating the square footage of a home. Instead, parameters for deciding the right-sized heat pump include the following:

  • Thickness of insulation
  • Number and size of windows
  • Number of occupants
  • Number and type of doors
  • Height of ceilings

Total square footage is still an important parameter to consider, but it is not the only one.

There is a variance in heating needs based on the above parameters. If an HVAC contractor only considers square footage, there is a good chance you’ll end up with the wrong-sized system.

Heat Pump Installation Day

Before heat pump installation day, you can ask for bios of the installation team that will be entering your home. Great HVAC companies accommodate this ask to ensure their clients feel safe and comfortable.

Once the team arrives, the lead installer can share and review job information with you. You’ll learn about equipment information, accessories, and any special instructions.

While the lead installer reviews important details with you, the other team members will begin laying down floor protection and gathering the necessary tools.

Disconnecting the Old Heat Pump

Before installing a heat pump, the existing one will get disconnected. The old heat pump contains a refrigerant that requires removal.

The EPA regulates the removal of this refrigerant. Under the law, technicians cannot openly vent the refrigerant into the atmosphere.

Professionals will use a recovery machine device and recovery tank to safely and legally remove the existing heat pump refrigerant.

Once the refrigerant is safely recovered, electrical wiring must get disconnected from the existing unit. An HVAC company can replace the disconnect box and the flexible electric conduit to ensure safety when replacing a heat pump.

If your old system lacks a disconnect box, you’ll need a new one as part of the installation with the new heat pump. Various safety and building codes require a new disconnect box.

The existing heat pump can be removed once the current connections are safely out of the way.

Prepping the Area

The location of the current heat pump needs prepping before it can be replaced with a new heat pump. Preparing the area involves replacing the pad that the old heat pump sits on.

Technicians can level the ground to set a new pad. They will use a gravel base to level out or build up the area where the new heat pump will go.

It’s recommended to use a composite pad that can last the lifetime of your new heat pump and is great for outdoor use.

Heat pumps must be above ground level to prevent the coils from piling up with snow and ice. This also allows proper draining for the heating system.

Removing the Indoor Evaporator Coil

The existing indoor evaporator coil is half of the heat pump source that needs to be removed. This component sits above the furnace but can sit below the furnace in some cases.

The other ends of the refrigerant lines connect to the evaporator coil.

An indoor evaporator coil has a cased and uncased variation. In each application, the sheet metal plenum will be disconnected before a new coil can be installed.

If technicians don’t have easy access to your coils, this process becomes complicated. The existing refrigerant line set of two copper lines can be removed once the technician has access to the set.

A new evaporator coil for your new heat pump will either be cased or uncased. Cased coils are preferred because they are insulated and have removable panels that allow you access to the inside coil.

A cased coil will sit on top of the furnace and requires no modifications or repairs.

A cased coil is technically “installed” already and only needs to be placed on top of the furnace. The final step of this is to connect and seal the coil to the existing sheet metal plenum.

An uncased coil without an insulated cabinet has more installation requirements and a longer preparation time. An uncased coil can be just as efficient as a cased coil if it is properly installed by the installation team.

Line Sets and Additional Wiring

Once the new evaporator coil is in place, a technician will remove the existing refrigerant line set.

The larger line, the suction line, and the smaller line, the liquid line, come together rolled in a coil. The line set runs from the heat pump outdoors to the new indoor evaporator coil that was installed.

To turn the heat pump on and off, an outdoor sensor has to be installed unless the thermostat is programmed to do it.

To disable the heat pump and use heat strips, extra wiring has to be disabled. Technicians will then form a line set.

Technicians will braze together the copper line set, the service valve, and the filler rod to prevent leaks.

Voltage Wiring Installation

The heat pump cannot operate without connecting the high and low-voltage wiring. An installer will mount a new service disconnect box using the existing power supply from the indoor electrical panel.

The low-voltage control wire is connected to the heat pump condenser according to the condenser installation instructions. This allows the heat pump to cycle based on the set parameters.

Before setting up the thermostat, the installer will start the low-voltage connection outside.

Commissioning Process

After the heat pump system is installed and ready to operate, the startup and commissioning process is completed. In other words, technicians will test your new heat pump.

Technicians will turn on the heat pump and allow it to run for about 15-20 minutes, which is enough time for the refrigerant to flow through the system.

Testing the heat pump can take up to two hours because a contractor will test the heating side, cooling side, emergency heat, and defrost. Testing each function will satisfy the requirements of getting the system under warranty.

During the commissioning process, an installer should check the system sequence of operation, thermostat operation, and other functions as well. This is the only way to know if your new heat pump is operating effectively.

Cleanup Process

The cleanup process is simple and something you won’t have to worry about when you hire professional heat pump installers. All old materials and equipment will get loaded up and taken away from your house.

Technicians will roll up the floor protection to keep debris from the installation out of your home.

After, technicians can sweep up areas that still have debris and materials. A great contractor will leave the area the same way that they found it.

Once your home is back to its original glory, a contractor will walk you through the completed installation. They will go over special instructions, safety, warranty, and maintenance.

They will give you an overview of the testing and thermostat processes. You’ll learn how to switch your heat pump from regular heat and emergency heat.

How Long Does Heat Pump Installation Take?

A typical heat pump installation can take up to eight hours. Installers will usually start the process in the morning and continue throughout the late afternoon.

Installation may take longer if there is inclement weather, unforeseen electrical complications, air duct alterations, etc.

You’ll get a more accurate timeline when you hire a heat pump installer for the job.

Benefits of Hiring a Professional

As you can see, heat pump installation is a lot more complex than some homeowners realize. This intensive process should always get completed at the hands of a professional.

If you try to install a heat pump yourself or sign up with an amateur service, your heat pump won’t last as long as it should.

These are the benefits you’ll experience when you hire a professional heat pump installer:

Correct Sizing

The wrong-sized heat pump won’t adequately heat up your home. You’ll have to deal with an uncomfortable temperature and a shorter heat pump life span.

An incorrectly sized heat pump can break down sooner from frequent short cycling. Professionals can measure equipment and calculate factors in your home that affect your heat pump sizing needs.

Increased Efficiency

With a professional heat pump setup, you’ll benefit from the most efficient system possible.

Professional installers work with heat pumps on a daily basis. They know the ins and outs of the installation process because they are trained and knowledgeable on the topic.

Ensures the New System Works

As you’ve learned, the last step in the heat pump installation process involves commissioning the new setup. Any great technician will stay after the installation to ensure your system works.

There are amateurs that won’t complete this final step because they only care bout getting paid.

To ensure you are working with a qualified professional, ask them about the installation steps. If they don’t say they are going to check your system, consider finding a contractor that does.

System Warranty

Heat pump manufacturers generally require that heat pumps are installed by licensed technicians. If you fail to meet this requirement, your warranty may become null and voided.

Getting your heat pump installed by professionals means you get expert servicing and you get to keep your warranty in play.

Save Money

Installing a heat pump on your own is going to come with problems. When you hire a professional, you might feel negative about the cost of labor, but it is worth it in the long run.

You’ll save money by hiring a professional that can install your heat pump right the first time without complications. An efficient installation means your system will last longer.

With the correct installation, you can also reap the various benefits of using a heat pump as your source of heat. Compared to gas, electric, and oil furnaces, heat pumps are more efficient.


If you don’t know what you are doing, installing a heat pump is dangerous. A professional contractor with experience will know the exact steps to take to protect you and your family from heat pump issues.

When installed correctly, heat pumps are a safer heating system compared to gas furnaces.

A gas furnace and other combustion-based heating systems can cause a carbon monoxide leakage. This is not something you’ll need to worry about when you have a heat pump.

Work With the Professionals!

There are a lot of steps required during a heat pump installation. Now that you know what your technician will perform, you can prepare for the process.

We know that installing a heat pump on your own is a challenge that you likely aren’t up for, and you don’t have to be. We are professionals in the industry for a reason.

Let our contractors at KD Mechanical install your new heat pump! Schedule servicing or request a quote today.

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