Pool heating guide

Best Pool Heat Pump Size for 40,000L and 50,000L Pools

Pools around 40,000L to 50,000L are common for Australian homes, and they sit in the range where heat pump sizing makes a noticeable difference. Too small and the heater may run for long periods without recovering well. Too large and the upfront cost may be more than the pool owner needs.

For pools under 40,000L

A 17kW inverter heat pump is usually a good starting point for pools under 40,000L, especially when a pool cover is used. This size can work well for smaller family pools where the goal is steady heating and efficient maintenance rather than rapid temperature rise.

For pools around 50,000L

For pools around 50,000L, a 21kW inverter pool heat pump is often the best fit. It is one of the most common practical choices in the Melbourne area because it balances heating strength, installation practicality and running cost.

What can change the recommendation?

Pool size is only one part of the decision. Wind, shade, cover use, desired water temperature and heating schedule can all shift the recommendation. An exposed 40,000L pool may need more heater than a protected 50,000L pool with a good solar cover.

Why pool covers matter

Most heat loss happens from the surface of the water. A cover reduces overnight heat loss and helps the heat pump maintain temperature more efficiently. If you plan to heat regularly, a cover is one of the best upgrades to combine with a heat pump.

View our pool heat pumps, or read the full pool heat pump sizing guide for more detailed sizing notes.