Pool Heat Pump Troubleshooting Guide

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Pool heat pumps are an affordable and energy-efficient way to heat your pool in the cooler months. But like other pool equipment, they can run into problems, like not heating your pool properly, leaking water or throwing up confusing error codes. Read on to discover six common pool heat pump problems and how to fix them.

1. Pool heat pump not turning on

First of all, check to see if your timer is set properly. This is a common reason why heat pumps don’t come on when they’re supposed to (particularly if you’re new to pool heat pumps). If the timer is correct, there could be a connection issue or your circuit breaker may have been activated. Make sure your unit is plugged in and that the circuit breaker is off. If the pump still doesn’t turn on, you may have faulty or corroded wires. In that case, call a technician for service or inspection.

2. Pool heat pump not heating or heating too slowly

There are a few reasons why your pool water may not be heating or heating too slowly. First, the ambient temperature may be too low. The cooler the air, the longer it’ll take to cool your pool water. If possible, move the unit to a sunny area or remove shade to improve heat absorption.

Second, there may not be enough space around the unit to ensure peak performance. Make sure you follow the recommendations in your pool heat pump guide and adjust as necessary. If you have limited space, opt for a slim-line model with vertical airflow, such as the Z400 iQ Pool Heat Pump.

Third, you could have low water flow, which won’t circulate pool water quickly enough, leaving you with lukewarm pool water or cold spots. Make sure the valves to the heat pump are open and that your filter is clean. If necessary, run your pool pump for longer and increase pressure to improve flow. If your heat pump is new, your pool pump may not be powerful enough to draw enough water into the heater. In that case, you may need to upgrade to a larger pool pump.

Fourth, your external evaporator coil may be obstructed by leaves, grass clippings and dirt. This can prevent it from drawing in enough air to warm up your pool water. To clean it, turn off the heat pump and disconnect the power while removing any large debris by hand . Next, rinse the coils with a hose, keeping the pressure low at all times.

Lastly, your thermostat may not be correctly programmed (or a power surge has reset it). In general, your thermostat temperature should be higher than your pool water temperature or the heater won’t heat your pool. If the temperature is correct, then you may have a faulty thermostat, in which case you’ll need to call a technician for advice or service.

3. Pool heat pump leaking water

There are two reasons why your pool heat pump may be leaking water: condensation or a leaking connection. To check, test the water to see if it contains any pool chemicals. If it doesn’t, it’s condensation, which is normal and nothing to worry about. If it does, then you may have a broken gasket, corrosion or cracks. Don’t try to fix these yourself. Call a technician for an inspection and service.

4. Pool heat pump error code

Each pool heat pump has error codes that correspond to a particular problem. Sometimes, if your heat pump isn’t working properly or there’s an internal problem, you’ll see an error message on the screen. It may tell you that there is insufficient water flow, low sensor temperature or low/high freon pressure.

Check your manual to see what you can do to fix these problems. Sometimes it’s as simple as waiting for the ambient temperature to rise if you’ve got a low sensor temperature or increasing water flow if the freon pressure is too high.

5. Pool heat pump shutting off

There are two main reasons why a heat pump may suddenly shut down. The first is when your ideal temperature is reached – which is perfectly normal. You’ll be able to confirm by checking your LED screen or mobile app.

The second reason is when you have low water flow. This is often due to a clogged filter or a full skimmer basket. Correct this problem by cleaning your pool filter cartridge or backwashing your media filter, replacing the cartridge or media (if necessary) and emptying your skimmer basket.

If it still keeps shutting off, then the water flow issue may be due to your pool pump. If it’s a variable-speed pump, increase the speed to trigger the heater and make sure it runs for at least 8 hours to heat the water to your desired temperature.

6. Pool heat pump ‘smoking’

There are two reasons why this might happen. If you live in a cold climate and ice has formed on the unit’s components, your pool heat pump will automatically go into defrost mode. This means it’ll use hot air to melt any ice or frost on the unit. When this happens, the water can turn into a gas, making it look like your unit is ‘smoking’. This is temporary and nothing to worry about.

If the outdoor temperature is warm and your pool heat pump hasn’t been through a defrost cycle, there may be a fault inside the unit. Turn off the pool heat pump immediately and call a pool technician.

How long does a pool heat pump last?

Pool heat pumps have a long lifespan and can last 10–20 years, depending on frequency of use and maintenance. That’s because heat pumps draw heat from the atmosphere, so they don’t have to work as hard or use as much energy to heat your pool.

By comparison, gas heaters only last about 5–10 years because they produce heat instantly and wear out quickly. Solar panels have the longest lifespan at around 15 years, but exposure to the elements can cause denting, rust or cockatoo damage, which may require regular servicing.

How to maintain a pool heat pump

To prevent or minimise problems in the future – and ensure your heat pump’s longevity – here are some maintenance tips:

Inspect your pool heat pump. Check for blockages, leaks and loose connections. Remove any debris clogging the ventilation grid with a soft brush or hose.
Ensure good circulation. To avoid water circulation issues that may stop your heater from activating or heating your pool, run your pool pump for at least 8–10 hours a day, and keep your filter, skimmer baskets and pool pump basket free of leaves and other environmental debris.
Operate during the day. Your unit will heat water faster and more efficiently if it runs during the warmer hours of the day.
Use a pool cover. To minimise heat loss and prevent overworking your pool heat pump, use a pool cover overnight or when your pool isn’t in use. Even if your pool temperature does drop, you won’t need to wait as long to heat your pool to the desired temperature.
Minimise water exposure. Keep your pool heat pump away from sprinklers or rain (check for gutters that may overfill with water). While most pool heat pumps are designed to withstand light rainfall, heavy applications of water may damage internal parts and prevent your pool heat pump from working properly.
Watch your pool chemistry levels. Unbalanced water can corrode your heat pump and reduce its longevity. To prevent this, keep your water chemistry levels within the correct range.
Winterise your pool heat pump. If you’re not using the pool heat pump for a few months or you’re closing your pool, it’s important to winterise it to prevent damage. Follow the instructions in your manual or seek advice from your local pool shop.
Book an annual service. Get an annual service from a licensed technician to check your heat pump’s control system, water flow, compressor, heat exchanger and cables. The technician will also give the inside of your unit a clean. Not only does a service keep your heat pump working at its best, but it also minimises expensive repairs further down the track.

Summing up

Don’t let your pool heat pump put a damper on your swimming season. By following our simple troubleshooting guide, you’ll be able to identify and fix common heat pump problems like a pro – and save yourself hundreds in call-out fees. But if your unit is still playing up, contact your local pool shop or call a licensed technician for expert advice.

To minimise malfunctions in the future, make sure you look after your pool heat pump by inspecting it regularly, ensuring good circulation, running the heat pump during the day, using a pool cover, avoiding water damage, keeping your water chemistry balanced, winterising the unit (if necessary) and scheduling an annual inspection.

Want more tips on how to maintain your pool equipment? Then dive back into our Pool & Spa Guides.