How to Install a Pool Heat Pump: Step-by-Step Guide

Raypak pool heater
photo: Raypak

Well done! You’ve bought a swimming pool heat pump, which is a great decision. You are now set to make considerable energy savings and enjoy comfortable pool temperatures all season. All you need to do now is install it.

Many pool heat pump manufacturers will offer you two different warranties – a shorter version if it’s self-installed and another, longer one, if you have it professionally installed. Other manufacturers may void the warranty entirely unless it is professionally fitted. It’s worth checking it out before you start.

You want your new investment to deliver long and efficient life, and the installation must comply with all local and state codes. If you are in any way unsure, then you should call in a professional installer. In this step-by-step guide, we will look at how to plan and work through the installation of your new pool heat pump, from selecting the right location to planning and preparing the site, the plumbing, and electrics. Plus, the mistakes to avoid. So, let’s get started.

Selecting the best location

HP installation layout and minimum clearances

It’s important to select the best location for your pool heat pump. It should never be installed in a closed space like a shed or garage with poor ventilation; it should always be outside, preferably in direct sunlight. This sketch below shows a possible layout for your new pool heat pump.

Preparing the site

If there isn’t one already in place, you will need to create a substantial, level base to suit the size and weight of your new unit. This can be concrete, block plinth, or any other suitable material. Make sure the stand is not directly attached to the house as this will transmit vibration and noise inside, and it could become annoying. The support should sit at the same level or a slightly higher level than the filter system pad.

As the heat pump requires proper airflow, you need to locate it in a sunny position away from shade, foliage, fences, or walls. It needs to have free airflow around it to work efficiently. Check for runoff from the roof onto the unit and avoid it with guttering as large volumes of rainwater and debris could enter the top of the heat pump and cause damage to the unit.

In the U.S., you must site the unit at least 60 inches from the inside wall of the pool’s fixed barrier. In Canada, there must be a minimum distance of 120 inches between the unit and the pool water (always check). In any case, keep the unit as close to the pool as is permitted to minimize cooling loss and maximize the water flow rate.

If the humidity in your area is high, a larger volume of condensate will drain from the unit, so ensure an effective drain pan hose is used to avoid water build-up and possible damage to the unit.

Installation tips

Allow a minimum of two feet between the back of the unit and the house, at least two feet in front and six feet above to ensure good airflow. If you install the unit under a low overhang, it may not get sufficient airflow to operate efficiently.

It’s also important to consider future access for servicing, so leave sufficient space around the unit for this purpose. This sketch shows the ideal minimums you should aim for:

Recommended minimum clearances

Plumbing tips

You will need the following minimum plumbing connections:

• 2 in. schedule 40 PVC pipe and 2 in. fittings.
• Isolation valves if a bypass is not already in place.
• A check valve to prevent chlorinated water from flowing back into the heat pump.
• Sacrificial anode.
• PVC Tee’s.

If you are replacing an existing pool heater, you may have to modify the plumbing layout to suit the new system, so the above items are only a guide, however, anything you need will be readily available locally.

Plan your plumbing layout carefully, using as few fittings as possible to connect your heat pump. If this is your first pool heater, then you can set the plumbing layout to suit your preferences. Plan carefully to avoid trip hazards with pipes and the chance of them being stood on and broken.

If you are using existing plumbing with your new heat pump, you may have to make some modifications to accommodate the new unit. The heat pump should always be installed after the filter unit and before the chlorinator or chemical feeder for your pool as shown in the sketch here:

Typical pool heat pump installation setup

Check valve

You need to fit a corrosion-resistant check valve (Shown in red above) between the heater outlet and your chemical feeder or chlorinator to stop any backflow of water containing chlorine or pool chemicals. These can accumulate inside your heater, corroding it and could ultimately cause it to fail. If there is no check-valve fitted, the manufacturer may reject any warranty claim for a damaged heater due to chemical corrosion.

Sacrificial anode

With a sacrificial anode fitted in your pool plumbing system (Shown in grey above), you can add a layer of protection from corrosion in your pool equipment. It is important to maintain the water chemistry of your pool balanced; however, corrosion is still an issue even in a well-balanced pool.

If you install an inline sacrificial anode, it will protect your pool and prevent corrosion in expensive heat exchangers. It is a cheap way to extend the life of your system by a factor of two or three times. A sacrificial anode is easy to install and inexpensive; it will safeguard your heat pump and give you peace of mind. 

Manual bypass system

It is important to fit a manual bypass system, with two isolation valves (Shown in brown above) which allows you to run the pool pump without running the heat pump. If the pool water temperature is high enough, you can save energy by switching the heat pump off. These valves also allow you to control the water flow through the heat pump to maximize its efficiency and prevent it from running too hot or too cold.

In addition, when you close the pool down for winter, you can close off the heat pump and drain it of all water, so it sits dry during the cold season, which will prevent corrosion and damage to the unit when it’s not in use.

Electrics

If you are replacing an existing pool heater, you must check to ensure the power supply is suitable for the new heat pump. If there’s no existing wiring in place, you will need to install a dedicated line to the specifications on the rating panel on the heat pump. An electrical disconnect switch MUST be installed within sight of the unit to enable power to be cut instantly in the event of an emergency.

To comply with all local codes and for your family’s safety, you will need to employ a qualified electrician to do this work for you.

Conclusion

With power in place and minimal plumbing work, you should be able to install your new pool heat pump in just a few hours. If you are starting from scratch, while you can tackle this job yourself, it is usually best and quicker to employ a professional installer, which means you will fully comply with the terms of your warranty for any future claims.

The annual energy savings you can expect will vary from location to location and your local climate. But pool heat pumps beat gas and electric heaters hands down for efficiency and economy under normal circumstances.

One other item you may consider is a pool cover, which will save the evaporation of water you have carefully heated. There are many types available to suit most budgets, have a look here for further details.

All electrical work must be undertaken by a qualified professional so that everything complies with local and state codes. Correct bonding and grounding are vital; it could save your life.

Once in place and running, your new heat pump will give you comfortable pool temperatures during the season at a cost that won’t break the bank.

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