What Size Thermotec Heat Pump Do I Need for My Pool?

If you want the quick answer, the right Thermotec heat pump depends on your pool volume, whether the pool is covered, how warm you want the water, and how much of the season you want to use it. Smaller above-ground pools often suit the Thermotec Mini or lower-output Neo models, while larger pools or buyers wanting stronger performance are usually better looking at the wider Thermotec heat pumps range, including Neo, Inverter Pro and Inverter Edge models.

It would be lovely if choosing a pool heat pump were as simple as pointing at the nearest one and saying, “That seems about right.” Sadly, water has no respect for optimism.

Getting the size right matters. A heat pump that is too small may struggle to bring the pool up to temperature or keep it there consistently. A model that is properly matched to the pool will heat more effectively, run more efficiently and generally make the whole experience feel much less like an expensive experiment.

In this guide, we’ll explain how to work out your pool volume, what affects sizing, and which Thermotec model is most likely to suit your setup.

How to work out your pool volume

Before choosing a Thermotec heat pump, the first job is to work out your pool volume in cubic metres (m³). It is not the glamorous part of the process, but it is the bit that stops you buying the wrong model and then glaring at the weather as though it is personally responsible.

Example: if your pool is 6m long, 3m wide and has an average depth of 1.2m, the volume would be 6 × 3 × 1.2 = 21.6m³.

What affects the right heat pump size?

Pool volume is the starting point, but not the whole story. The right size also depends on:

• whether the pool is covered
• whether it is above ground or in ground
• how exposed it is to wind
• the temperature you want to maintain
• whether you want peak summer use or a longer season
• how quickly you want the pool to heat

As a rule, if the pool is uncovered, exposed, or you want to swim earlier and later in the season, it is usually better to size up rather than choose the smallest model that might just about cope on paper.

It is also worth saying that pool covers matter more than many people expect. Covering the pool helps reduce heat loss and keeps running costs more sensible, which is always preferable to paying to warm the entire neighbourhood.

Which Thermotec heat pump range is right for you?

Thermotec Mini: best for smaller above-ground pools

The Thermotec Mini Heat Pump 5kw Reversible for Above Ground Pools is the natural starting point for smaller above-ground pools and simpler family setups. It is compact, practical and ideal if you want straightforward summer heating without overcomplicating matters.

The Mini is best suited to smaller above-ground pools up to around 10m³, and makes the most sense when you want a compact option for the main summer season rather than a more powerful multi-season setup.

Thermotec Neo: best for efficient everyday heating

The Thermotec Neo Inverter Heat Pump is the next step up and covers a much broader range of pool sizes. It is a strong option for buyers who want inverter efficiency, quieter running and more flexibility across both above-ground and in-ground pools.

If you have an above-ground pool and want a proper step up from the Mini, Neo is usually where things start to feel more flexible.

Thermotec Inverter Pro: best for broader pool sizes and stronger output

The Thermotec Inverter Pro Pool Heat Pumps range covers both horizontal and vertical models, so it spans everything from smaller and medium pools right up to very large and more demanding installations.

If you need stronger all-round performance, more headroom or a model that covers a very large pool, Inverter Pro is where the range starts to feel much more serious.

Thermotec Inverter Edge: best for premium inverter performance

The Thermotec Inverter Edge Pool Heat Pumps range is the more premium-feeling option, with strong inverter performance and model sizes aimed at medium through very large pools.

If you want a more premium inverter option and a bit more polish in the overall setup, Edge is a very sensible place to look.

Quick Thermotec sizing guide by pool type

For smaller above-ground pools

Start by looking at the Thermotec Mini or the lower-output Neo models.

For medium above-ground pools

The Neo range is often the best fit, especially if you want quieter inverter performance and more flexibility.

For larger family pools

Move into the bigger Neo models, or into Inverter Pro and Inverter Edge if you want stronger all-round performance.

For very large or more demanding pools

Inverter Pro vertical models and larger Inverter Edge models are usually the more appropriate options.

Should you size to the recommended maximum or the absolute maximum?

In most cases, aim closer to the recommended maximum rather than the absolute maximum.

The absolute maximum is more of an upper limit than a comfort zone. If your pool volume is right up against that figure, the heat pump may still work, but it is more likely to have to work harder and you may get better real-world results by stepping up to the next model.

That is especially true if:

• your pool is uncovered
• your garden is exposed to wind
• you want faster heating
• you want to extend the season

What about koi ponds?

If you are sizing for a koi pond rather than a swimming pool, the answer changes a bit.

Neo can be used for koi ponds in some cases, but the guidance we gathered suggests that Thermotec Inverter Pro models are generally the better fit for koi pond use because they offer stronger output in colder conditions. Neo can still work, but often with an electric backup heater for colder weather.

Our advice

If your pool is small and above ground, start with the Thermotec Mini Heat Pump 5kw Reversible for Above Ground Pools.

If you want a broader range of sizes and a more refined inverter option, look at the Thermotec Neo Inverter Heat Pump.

If your pool is larger or you want stronger performance and more headroom, compare the Thermotec Inverter Pro Pool Heat Pumps and Thermotec Inverter Edge Pool Heat Pumps.

And if you would rather compare everything in one place first, browse the full Thermotec heat pumps range.

Final thought

The right heat pump size is really about making your pool more usable, more comfortable and less dependent on the sort of weather forecast that gets everyone’s hopes up and then changes its mind overnight.

Get the sizing right, and the whole thing becomes much simpler.

Have you checked out our other posts?

Thermotec Mini vs Neo vs Inverter Pro vs Inverter Edge | Which Is Best?