Collection: Air Source Heat Pumps for Hot Tubs & Swim Spas

Your hot tub’s biggest running cost is heat.
A heat pump is the upgrade that changes how hot tub ownership feels: instead of constantly “re-heating” expensive water, you keep your spa at a stable temperature efficiently — so it’s ready more often, with far less energy waste.

What is a hot tub heat pump?

A hot tub air source heat pump is basically a smart heater that moves heat rather than “making” heat.

• A traditional electric heater works like a kettle: it turns electricity directly into heat. Simple, but expensive to run for long periods.

• A heat pump works like a refrigerator in reverse: it pulls warmth from the outside air and transfers it into your spa water.

That’s why you’ll see terms like COP (Coefficient of Performance). COP is just a fancy way of saying: “How much heat do I get back for the electricity I use?”
If a unit is operating at a COP of 5, it’s producing roughly 5 units of heat for every 1 unit of electricity (conditions affect this — more on that below).

Why most owners benefit from a heat pump

If you use your tub regularly (or want to), a heat pump usually gives you three big wins:

1) Lower running costs
Heating is where most of the electricity goes. Heat pumps can reduce how hard your spa’s internal heater has to work.

2) Your tub becomes “always ready”
The best hot tub is the one you actually use. A heat pump makes it easier to keep your water at temperature without feeling guilty every time you look at the meter.

3) Quieter, smoother heating (especially inverter models)
Many modern spa heat pumps use inverter technology, which means the compressor can ramp up and down smoothly instead of loud on/off cycling. That often means less noise and more stable water temperature.

Do you need one?

You don’t “need” one in the way you need water. You need one in the way you need central heating: if you want comfort without pain, it’s the sensible upgrade.

A heat pump is especially worth it if:

• You keep your hot tub warm most of the week

• You use it in spring/autumn/winter (UK reality)

• You’ve got a larger tub or a swim spa

• You want the spa to feel like a routine, not a project

How to pick the right heat pump

Most people pick wrong for one of two reasons: they buy based only on kW, or they ignore real-world conditions.

Here’s a clean way to choose:

1) Match kW to your water volume + how fast you want recovery

• Smaller tubs / light use: lower kW can be perfect for maintenance heating.

• Bigger tubs / heavy use / cold months: more kW gives faster recovery and more headroom.

If you want the simple rule:
Bigger water + colder weather + faster “back to temp” = higher kW.

2) Check cold-weather performance

Heat pumps are affected by outdoor temperature. A model that performs well in low ambient temps matters if you’re using your tub year-round.

Look for:

• Stated operating range (how cold it can run)

• Realistic expectations: it may run longer in colder weather, but still far more efficiently than direct electric heating.

3) Prioritise inverter if you care about noise and comfort

If you want the most “premium ownership” feel, inverter models usually win because they:

• Maintain temperature more smoothly

• Run quieter during maintenance heating

• Avoid aggressive on/off cycling

4) Make sure it fits your space (clearance + airflow)

Heat pumps need breathing room. If airflow is blocked, performance drops.
Plan for:

• Side and rear clearance

• Overhead clearance for top-discharge models

• A sensible location that doesn’t aim cold exhaust air at a seating area

Installation basics (what to expect)

Most spa heat pumps are installed with a bypass in your plumbing so you can control flow correctly and isolate the unit if needed. Proper installation = better efficiency + less hassle.

A good setup includes:

• Correct plumbing/bypass

• Proper electrics

• Clear airflow

• Sensible placement for noise and exhaust air direction

The Within Wellness approach

We curate heat pumps that make hot tub ownership easier — not more technical. That means focusing on:

• Efficient performance (especially for UK seasons)

• Quiet operation (so your garden still feels like a garden)

• Reliable builds designed for spa water environments

• Options for different tub sizes and usage patterns

If you’re not sure which one to choose, the “right” answer is the one that matches your water volume, your use frequency, and whether you want fast recovery or maximum efficiency.