Looking to reduce running costs on your hot tub or swim spa? Investing in an air source heat pump is the smart, energy-efficient solution.
As one of our best-selling hot tub accessories, air source heat pumps are already helping hundreds of UK customers enjoy their spa experience while saving money. Designed for the British climate, these pumps offer quicker heating times and improved energy efficiency, making them an essential upgrade for modern outdoor living.
An air source heat pump is an energy-efficient heating system that draws heat from the air to warm your hot tub or swim spa. It works alongside your existing system or replaces it, helping you heat your spa more efficiently and affordably.
If you use your hot tub or swim spa regularly, an air source heat pump can save you up to 75% on your energy bills. It’s a smart investment that provides reliable heating while reducing running costs.
Yes! They’re designed to perform efficiently in all seasons, even in colder UK weather, so you can enjoy your hot tub or swim spa any time of year.
We recommend Vian Power – a trusted, well-known brand that designs pumps specifically for hot tubs and swim spas. They’re reliable, efficient, and tailored to UK conditions.
Installation requires professional plumbing and electrical work, so it must be done by an experienced hot tub technician. We offer standard delivery and installation included within our service area.
If you’re considering upgrading your hot tub or swim spa with an air source heat pump, give us a call today on
UK Hot Tubs: 02382 687 005 | Spafix: 02393 541 154
Our friendly, knowledgeable team is always happy to help with any questions or advice you need — and we’ll get back to you as quickly as possible.
Do I need additional electrical work?
No extra electrics are needed! The heat pump draws power directly from your hot tub or swim spa, so there’s no need for a separate supply.
Do I need planning permission?
No planning permission is usually required. However, every installation is different, so we offer a free site survey (for local clients) to assess the best location and setup for your heat pump.
What’s involved in the installation?
Our technician will make some simple modifications to your hot tub or swim spa, adding an inlet and outlet pipe to allow water to circulate through the heat pump for efficient heating.
Where does the heat pump need to be placed?
The unit needs a minimum of 450mm of clear space for air intake, and at least 1500mm in front of the fan outlet to ensure proper airflow and performance.
Due to how the system works, our air source heat pump will still produce heat even if the ambient air temperature is below zero as the compression of the refrigerant creates heat. Not only is this a far more cost-effective solution to heat your hot tub, it is also a much more eco-friendly option.
The chart below shows the kilowatt hours (kWh) used by the air source heat pump to maintain a constant water temperature of 40°C. The test was carried out over a 31-day period, running from the 8th of December 2022 to the 7th of January 2023.
This proved to be an ideal timeframe for performance testing, as it began during a particularly cold spell in the UK, with temperatures dropping several degrees below freezing. On the 10th of December 2022, for example, the recorded ambient temperature was -3.1°C. As shown in Figure 1, the heat pump used 5.62 kWh of electricity on that day to maintain the desired temperature.
By comparison, later in the test period, on the 4th of January 2023, the outside temperature had risen to 11.5°C. As seen in Figure 2, the heat pump used just 1.66 kWh to maintain the same water temperature of 40°C.
In total, the heat pump consumed 116.21 kWh over the full 31-day period, giving an average daily usage of 3.75 kWh. These results clearly demonstrate that as the ambient air temperature increases, the efficiency of the heat pump also improves significantly, making it a highly effective and energy-conscious solution for heating hot tubs and swim spas—even during colder UK winters.
The performance test was carried out in Chichester, West Sussex, UK with a Vian 7kW S7 Plus Air Source Heat Pump. During the test, the electric heater was fully disconnected, ensuring that all heating was supplied by the heat pump alone.
The hot tub used for the trial is a mid-specification model with a capacity of approximately 1,550 litres, located outdoors and completely unsheltered.
To reflect more realistic, everyday usage, the tub was fitted with an older, slightly waterlogged cover, and the pipes leading to the heat pump were not insulated. The heat pump was positioned within one metre of the hot tub.
The heat pump was set to operate in boost mode, and programmed to maintain a water temperature of 40°C. For energy management purposes, the hot tub followed an economy cycle that prevented it from heating between 10:00 PM and 10:00 AM daily, and again from 1:00 PM to 4:00 PM, seven days a week.
To calculate the heating cost, we used the Ofgem rate of 27.35 pence per kWh (as of 1st October 2023).
On 10th December 2022, with temperatures below zero, the heat pump used 5.62 kWh, costing £1.53.
By comparison, on the 4th January 2023, with milder temperatures of 11.5°C, it used only 1.66 kWh, costing £0.45.
Over the 31-day test period, the average daily usage was 3.75 kWh, equating to an average daily cost of £1.03.
We continued monitoring the heat pump’s energy usage throughout the winter, spring, and summer months, covering a 10-month period from 8th December 2022 to 7th September 2023. The chart and table below display the total kWh consumed by the hot tub’s air source heat pump each month during this time.
In Summary
Over the 10-month test period, the heat pump used a total of 749.55 kWh. This resulted in an average monthly consumption of 74.96 kWh, costing approximately £20.50 per month.
When broken down to a daily average, the heat pump used 2.46 kWh and cost just £0.67 per day, based on a 365-day year.
Overall, the total cost for 10 months of usage was £205.00 at the current rate of 27.35 pence per kWh.
From 1st October 2023 new kWh rate will be set at 27.35p website reference (Ofcom)
These recordings and data are only for representative purposes as there are so many variables with different locations, temperatures and usage that could result in different figures.
Whilst not independently vetted, we have performed this test to measure the kWh power consumption of our Vian 7kw S7 plus heat pump to show some of the real-world results.
We used a simple inline kWh meter that connects to a smart home system to measure and record the usage.
We chose to undertake this testing during the colder months and incorporate a very cold period of weather to record the results in these conditions. As the ambient temperature increases through the seasons then the efficiency of the heat pumps will increase, and the kWh usage will reduce as can be seen with the longer-term testing results.
Our figures and recordings are only relating to the consumption of the air source heat pump. Whilst fitting an air source heat pump to your hot tub or Swim Spa will significantly reduce overall running costs it will only reduce costs pertaining to heating.
We believe it is clear to see that a Vian Power Heat Pump is an extremely efficient heating solution for your hot tub or Swim Spa.
