How to Winterise Your Pool Heat Pump

How to Winterise Your Pool Heat Pump

Your pool heat pump is a valuable piece of equipment and so you should ensure that you protect it from damage that can be caused over winter.

If water is left in the heat pump over winter, then it can freeze to ice, expand and crack the heat exchanger in your heat pump.

This can be an expensive mistake and the cost of repairing the heat pump may be more than the unit is worth.

It is therefore worth taking a few basic steps to protect your heat pump during the winter.


Outdoor Pools

If you have an outdoor pool, then you will probably only use it during the winter months and your heat pump will be turned off during winter.

When your heat pump is installed, we recommend that a bypass kit is installed on the pipework.

The bypass kit allows your heat pump to be isolated from the water flow.











In winter, you should close the valves going in and out of the heat pump and open the bypass valve.

If you need a bypass kit, we sell them on our web site at

You can then loosen the connections to the front of the heat pump to allow all of the water to drain out of it.

Once the water has drained out of the heat pump, you should protect it by covering it with one of our top quality heat pump winter covers

Pool heat pump winter cover











Our winter covers are custom made to fit your model of heat pump.

They include special ventilation strips to allow any trapped moisture to escape and prevent corrosion of your heat pump.

You can see details of our winter covers on our web site at


Indoor Pools

Many indoor pools are used all year round.

In this case it is not possible to drain the water from the pool heat pump if the heat pump is still being used to heat the pool.

The heat pump must however still be protected from water freezing inside the unit during winter.

The best way to prevent freezing damage to the heat pump is to ensure that the pool pump is running whenever the air temperature falls below freezing (0c)

A frost stat should be fitted to the pool pump that automatically turns the pool pump on when the air temp falls below about +3c

Alternatively the pool pump can be set to run all of the time to keep the water moving and prevent it from freezing.

As long as the water is moving it will not freeze and will prevent damage to your heat pump.

If you do not use the heat pump during the winter, then drain the heat pump down and cover it as mentioned above for outdoor pools

Koi Ponds

Koi Pond Heat Pump from HeatPumps4Pools












Koi ponds are typically heated during the winter months.

Our Duratech Dura+ range of heat pumps are well suited to koi ponds as they operate down to -15c

As the heat pump will be used during the winter, it is not possible to drain the unit down.

A frost stat should be installed to ensure that the water pump is always running when the air temp falls below 0c

The procedure is the same as for indoor pools – see above


A pool heat pump is a valuable piece of equipment and when looked after will provide many years of service.

By draining down the heat pump, or by keeping the pool pump running, you can prevent damage from occuring to your unit over winter.

We hope that you found these tips useful.

Please let us know if you have any queries

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