The best air source heat pump for hot tub owners in Kent and the South East depends on the size of your tub and how often you use it, but our top five picks are the Fairland InverX, the Hayward EnergyLine Pro, the Zodiac Z400 iQ, the Madimack InverECO and the Duratech spa heat pump.
Each one takes free warmth from the outside air and uses it to heat your hot tub water, typically using a third to a quarter of the electricity of the standard electric heater built into most hot tubs.
At Guscott Heating, we install air source heat pumps across Kent and the South East. This guide reviews the five heat pumps our engineers rate most highly for hot tubs, explains what they cost to buy and run, and shows you how to choose the right one for your garden.
5 Best Air Source Heat Pumps for Hot Tubs: A Quick Overview
The 5 best air source heat pumps for hot tubs offer very different balances of price, efficiency and features, so we have summarised the key facts below. Prices are approximate and vary by retailer and size.
| Heat pump | Best for | Typical output | Efficiency (COP) | Approx. unit cost | Approx. installed cost | Est. winter heating cost per month | Typical warranty | Best property types |
| Fairland InverX | Year round efficiency | Around 5 to 9 kW | Up to around 7 to 15 in warm weather, 3 to 5 in winter | £1,200 to £1,900 | £1,600 to £2,600 | £12 to £18 | Typically 2 to 3 years | Family homes with regular year round use |
| Hayward EnergyLine Pro | Best value | Around 5 to 9 kW | Around 4 to 6 in mild weather, 3 to 4 in winter | £900 to £1,400 | £1,300 to £2,100 | £15 to £22 | Typically 2 years | Budget conscious owners and rental lets |
| Zodiac Z400 iQ | Smart control and swim spas | Around 7 kW upwards | Up to around 7 to 14 in warm weather, 3 to 5 in winter | £2,000 to £2,900 | £2,500 to £3,600 | £12 to £18 | Typically 3 years | Large hot tubs, swim spas and premium gardens |
| Madimack InverECO | Quiet gardens | Around 5 to 9 kW | Up to around 7 to 15 in warm weather, 3 to 5 in winter | £1,300 to £2,000 | £1,700 to £2,700 | £12 to £18 | Typically 2 to 3 years | Terraced homes and close neighbours |
| Duratech spa heat pump | Small and inflatable tubs | Around 3 to 5 kW | Around 4 to 5 in mild weather, 2.5 to 3.5 in winter | £600 to £1,000 | £800 to £1,400 | £15 to £22 | Typically 1 to 2 years | Smaller gardens, flats with patios, holiday lets |
Ratings: Which? does not currently test or rate hot tub heat pumps, so there are no Which? scores for these products. Trustpilot scores for each brand are listed in the individual reviews below.
Grants: hot tub heat pumps are not eligible for the Boiler Upgrade Scheme, which only covers heat pumps that heat your home.
Running costs assume a 1,200 litre hot tub kept at 38°C with a good insulated cover, needing around 6 kWh of heat a day in winter and electricity at around 26p per kWh. On the same basis, the tub’s built in 3 kW electric heater would cost roughly £45 to £50 a month. COP stands for coefficient of performance: a COP of 4 means you get four units of heat for every unit of electricity.
Want to cut your hot tub running costs? Guscott Heating provides air source heat pump installation across Kent and the wider South East. We can advise on the right heat pump for your hot tub, as well as for heating your home. Request your free heat pump estimate today.
5 Best Air Source Heat Pumps for Hot Tubs: Recommended by Our Engineers
The 5 best air source heat pumps for hot tubs recommended by our engineers are the models we trust to heat a tub efficiently through a Kent winter without fuss. Here is our detailed review of each one.
1. Fairland InverX: Best for Year Round Hot Tub Use
The Fairland InverX is the best choice for year round hot tub use because its full inverter design adjusts its speed to match demand, so it sips electricity once the water is up to temperature. Fairland is one of the world’s best known makers of inverter pool and spa heat pumps, and the InverX range has been a popular choice in UK gardens for several years.
Fairland InverX at a Glance
| Specification | Details |
| Key features | Full inverter, titanium heat exchanger, Wi Fi app on many models, quiet running |
| Efficiency | COP of around 3 to 5 in winter, much higher in warm weather |
| Estimated cost | £1,200 to £1,900 (unit), £1,600 to £2,600 (installed) |
| Cost with Boiler Upgrade Scheme | Not eligible, so no change |
| Running costs | Around £12 to £18 a month in winter |
| Output | Around 5 to 9 kW |
| Best for | Year round use in family homes |
| Warranty | Typically 2 to 3 years |
| Which? rating | Not rated by Which? |
| Trustpilot rating | [Add current score] |
Features
The InverX uses a variable speed compressor and fan, so instead of switching on and off it slows right down when it only needs to top up heat. It has a titanium heat exchanger, which resists corrosion from chlorine and bromine, and many models come with Wi Fi control through a smartphone app. It also runs quietly, which matters in tighter gardens.
Efficiency
In warm weather, Fairland quotes very high efficiency figures, with COP figures well into double digits at partial output. In a typical Kent winter, with air temperatures of around 5°C to 10°C, real world efficiency is more likely to sit around 3 to 5, which still means far less electricity than a standard 3 kW hot tub heater.
Unit and Installation Costs
Smaller InverX models suited to hot tubs typically cost around £1,200 to £1,900. With plumbing, electrical work and a base, the total installed cost usually comes to around £1,600 to £2,600.
Running Costs
For a 1,200 litre hot tub with a good cover, you can expect winter heating costs of around £12 to £18 a month, compared with roughly £45 to £50 for the built in electric heater.
Output
The smaller InverX models produce around 5 to 9 kW of heat, which is more than enough for most four to six seat hot tubs and helps the water recover quickly after use.
Warranty
Warranties typically run for around 2 to 3 years, depending on the retailer and model. Check whether the warranty covers parts and labour.
Best Property Types
The InverX suits family homes where the hot tub is used several times a week all year, such as detached and semi detached homes in Kings Hill (ME19), Tonbridge (TN10) and Herne Bay (CT6).
Ratings
Which? does not rate hot tub heat pumps. Trustpilot rating: [Add current Fairland Trustpilot score].
Should You Choose the Fairland InverX?
Choose the Fairland InverX if:
- You use your hot tub regularly through autumn and winter.
- You want low running costs and quiet operation.
- You like controlling your hot tub temperature from your phone.
Do not choose the Fairland InverX if:
- You only use your hot tub occasionally in summer.
- You are working to the smallest possible budget.
- You have a very small inflatable tub that does not need this much power.
2. Hayward EnergyLine Pro: Best Value Hot Tub Heat Pump
The Hayward EnergyLine Pro is the best value hot tub heat pump on our list because it offers a trusted brand, solid build quality and big savings over electric heating at a lower price than most inverter models. Hayward is an American pool equipment specialist founded in 1925, and its products are widely used by pool and spa professionals across Europe.
Hayward EnergyLine Pro at a Glance
| Specification | Details |
| Key features | Simple digital controls, tough casing, titanium heat exchanger |
| Efficiency | COP of around 3 to 4 in winter, 4 to 6 in mild weather |
| Estimated cost | £900 to £1,400 (unit), £1,300 to £2,100 (installed) |
| Cost with Boiler Upgrade Scheme | Not eligible, so no change |
| Running costs | Around £15 to £22 a month in winter |
| Output | Around 5 to 9 kW |
| Best for | Value for money and holiday lets |
| Warranty | Typically 2 years |
| Which? rating | Not rated by Which? |
| Trustpilot rating | [Add current score] |
Features
The EnergyLine Pro has a straightforward digital control panel, a tough weatherproof casing and a titanium heat exchanger to cope with treated hot tub water. Its design is simpler than full inverter models, which keeps the price down and makes it easy for engineers to service.
Efficiency
In mild weather, the EnergyLine Pro typically achieves a COP of around 4 to 6. In a Kent winter, expect around 3 to 4. It is not quite as efficient as the best inverter models at low loads, but it still uses far less electricity than a built in electric heater.
Unit and Installation Costs
Smaller EnergyLine Pro models suited to hot tubs usually cost around £900 to £1,400, with total installed costs of around £1,300 to £2,100.
Running Costs
For a 1,200 litre hot tub with a good cover, winter heating costs typically work out at around £15 to £22 a month, still less than half the cost of the standard electric heater.
Output
Models suited to hot tubs produce around 5 to 9 kW, enough for most standard four to seven seat hot tubs.
Warranty
Warranty cover is typically around 2 years, depending on where you buy. Hayward has a well established European parts network, which helps if repairs are ever needed.
Best Property Types
The EnergyLine Pro suits owners who want lower bills without paying top prices, including homes in Chatham (ME5), Sittingbourne (ME10) and Ashford (TN23), and landlords running holiday lets with a hot tub on the Kent coast.
Ratings
Which? does not rate hot tub heat pumps. Trustpilot rating: [Add current Hayward Trustpilot score].
Should You Choose the Hayward EnergyLine Pro?
Choose the Hayward EnergyLine Pro if:
- You want big savings over electric heating for a modest upfront cost.
- You value a well known brand with good parts support.
- You run a holiday let and want a reliable, easy to service unit.
Do not choose the Hayward EnergyLine Pro if:
- You want the lowest possible running costs in winter.
- Quiet operation is essential because the unit sits near a neighbour.
- You want app control as standard.
3. Zodiac Z400 iQ: Best for Smart Control and Swim Spas
The Zodiac Z400 iQ is the best choice for smart control and swim spas because it combines a powerful inverter heat pump with app control through Zodiac’s iAquaLink system. Zodiac is a French pool equipment brand, now part of the Fluidra group, one of the largest pool and wellness equipment companies in the world.
Zodiac Z400 iQ at a Glance
| Specification | Details |
| Key features | Inverter technology, iAquaLink app control, titanium heat exchanger |
| Efficiency | COP of around 3 to 5 in winter, much higher in warm weather |
| Estimated cost | £2,000 to £2,900 (unit), £2,500 to £3,600 (installed) |
| Cost with Boiler Upgrade Scheme | Not eligible, so no change |
| Running costs | Around £12 to £18 a month in winter for a standard hot tub |
| Output | From around 7 kW |
| Best for | Smart control, large hot tubs and swim spas |
| Warranty | Typically 3 years |
| Which? rating | Not rated by Which? |
| Trustpilot rating | [Add current score] |
Features
The Z400 iQ uses inverter technology to adjust its output to demand, a titanium heat exchanger and a built in connection to the iAquaLink app. That lets you check the water temperature, change settings and set schedules from your phone, which is handy if you want the tub ready for when you get home. It is designed with quiet running in mind.
Efficiency
In warm weather, Zodiac quotes high COP figures at partial output. In a Kent winter, expect real world efficiency of around 3 to 5, similar to other leading inverter models.
Unit and Installation Costs
The Z400 iQ is a premium product, typically costing around £2,000 to £2,900 for the smaller sizes, with installed costs of around £2,500 to £3,600.
Running Costs
For a 1,200 litre hot tub with a good cover, winter heating costs are likely to be around £12 to £18 a month. Larger swim spas hold several times more water, so running costs scale up accordingly.
Output
The smallest models start at around 7 kW, which makes this range well suited to large hot tubs and swim spas, where extra power helps the water heat up and recover quickly.
Warranty
Warranty cover is typically around 3 years, depending on the retailer. Check the terms for parts and labour.
Best Property Types
The Z400 iQ suits larger gardens and premium installations, such as detached homes in Sevenoaks (TN13), Tunbridge Wells (TN2) and the villages around Canterbury (CT4), especially where there is a swim spa or a large family hot tub.
Ratings
Which? does not rate hot tub heat pumps. Trustpilot rating: [Add current Zodiac Trustpilot score].
Should You Choose the Zodiac Z400 iQ?
Choose the Zodiac Z400 iQ if:
- You have a large hot tub or swim spa.
- You want full app control and scheduling.
- You are happy to pay more for a premium, well supported brand.
Do not choose the Zodiac Z400 iQ if:
- You have a small or inflatable hot tub.
- Keeping the upfront cost low is your priority.
- You do not need smart features.
4. Madimack InverECO: Best Quiet Hot Tub Heat Pump
The Madimack InverECO is the best quiet hot tub heat pump on our list because its inverter design lets it run slowly and softly once the water is warm, which suits gardens with close neighbours. Madimack is an Australian pool heat pump specialist whose products are sold across Europe and the UK, and the InverECO range is one of its most popular lines.
Madimack InverECO at a Glance
| Specification | Details |
| Key features | Full inverter, quiet running, titanium heat exchanger, Wi Fi on many models |
| Efficiency | COP of around 3 to 5 in winter, much higher in warm weather |
| Estimated cost | £1,300 to £2,000 (unit), £1,700 to £2,700 (installed) |
| Cost with Boiler Upgrade Scheme | Not eligible, so no change |
| Running costs | Around £12 to £18 a month in winter |
| Output | Around 5 to 9 kW |
| Best for | Quiet gardens and close neighbours |
| Warranty | Typically 2 to 3 years |
| Which? rating | Not rated by Which? |
| Trustpilot rating | [Add current score] |
Features
The InverECO has a variable speed compressor and fan, a titanium heat exchanger and an easy to use control panel, with Wi Fi control on many models. Its compact casing is designed to tuck neatly beside a hot tub or garden wall.
Efficiency
In warm weather, Madimack quotes very high COP figures at partial output. In a Kent winter, real world efficiency is typically around 3 to 5, in line with other leading inverter models.
Unit and Installation Costs
Smaller InverECO models suited to hot tubs typically cost around £1,300 to £2,000, with installed costs of around £1,700 to £2,700.
Running Costs
For a 1,200 litre hot tub with a good cover, expect winter heating costs of around £12 to £18 a month.
Output
Models suited to hot tubs produce around 5 to 9 kW, enough for most standard hot tubs.
Warranty
Warranty cover is typically around 2 to 3 years, depending on the retailer and model.
Best Property Types
The InverECO is ideal for terraced and semi detached homes where the unit sits close to a boundary, which is common in Gillingham (ME7), Margate (CT9), Ramsgate (CT11) and Gravesend (DA12).
Ratings
Which? does not rate hot tub heat pumps. Trustpilot rating: [Add current Madimack Trustpilot score].
Should You Choose the Madimack InverECO?
Choose the Madimack InverECO if:
- Your hot tub sits close to a bedroom window or a neighbour’s garden.
- You want inverter efficiency at a mid range price.
- You use your hot tub regularly through the year.
Do not choose the Madimack InverECO if:
- You want the cheapest possible unit.
- You have a large swim spa that needs more power.
- You want a brand with the largest UK service network.
5. Duratech Spa Heat Pump: Best for Small and Inflatable Hot Tubs
The Duratech spa heat pump is the best choice for small and inflatable hot tubs because it is compact, affordable and sized for smaller volumes of water. Duratech is a pool and spa equipment brand known for budget friendly heat pumps designed specifically for hot tubs and small pools.
Duratech Spa Heat Pump at a Glance
| Specification | Details |
| Key features | Compact size, titanium heat exchanger, simple digital controls |
| Efficiency | COP of around 2.5 to 3.5 in winter, 4 to 5 in mild weather |
| Estimated cost | £600 to £1,000 (unit), £800 to £1,400 (installed) |
| Cost with Boiler Upgrade Scheme | Not eligible, so no change |
| Running costs | Around £15 to £22 a month in winter for a standard hot tub |
| Output | Around 3 to 5 kW |
| Best for | Small, compact and inflatable hot tubs |
| Warranty | Typically 1 to 2 years |
| Which? rating | Not rated by Which? |
| Trustpilot rating | [Add current score] |
Features
The Duratech spa heat pump is a compact unit with a titanium heat exchanger and simple digital controls. Its small footprint makes it easy to fit on a patio or balcony, and smaller models are designed to work with the lower water flow of many inflatable and compact hot tubs.
Efficiency
In mild weather, expect a COP of around 4 to 5. In colder Kent winters, efficiency usually drops to around 2.5 to 3.5. That is still far cheaper than an electric heater, though not as efficient as the inverter models above.
Unit and Installation Costs
Duratech spa heat pumps typically cost around £600 to £1,000, with installed costs of around £800 to £1,400, depending on the electrical work needed.
Running Costs
For a 1,200 litre hot tub with a good cover, winter heating costs are likely to be around £15 to £22 a month. Smaller inflatable tubs hold less water, so they typically cost less to heat.
Output
Duratech spa models typically produce around 3 to 5 kW, which is ideal for inflatable and compact two to four seat tubs but can be slow to heat larger hot tubs from cold.
Warranty
Warranty cover is typically around 1 to 2 years, so check the terms carefully before you buy.
Best Property Types
The Duratech suits smaller gardens and patios, such as town houses in Folkestone (CT20), Rochester (ME1) and Tunbridge Wells (TN1), as well as landlords offering a hot tub at holiday lets in Broadstairs (CT10) or Deal (CT14).
Ratings
Which? does not rate hot tub heat pumps. Trustpilot rating: [Add current Duratech or retailer Trustpilot score].
Should You Choose the Duratech Spa Heat Pump?
Choose the Duratech spa heat pump if:
- You have an inflatable or compact hot tub.
- You want the lowest upfront cost.
- You have limited space on a patio or small garden.
Do not choose the Duratech spa heat pump if:
- You have a large hot tub or swim spa.
- You use your hot tub a lot in the depths of winter.
- You want a long warranty or smart app control.
How We Chose the Best Air Source Heat Pumps for Hot Tubs for Kent and South East Properties
We chose the best air source heat pumps for hot tubs for Kent and South East properties using the same practical checks our engineers use every day when designing and installing heat pumps across the region. Every model on this list was judged on how it would perform in a real Kent garden, not just on its spec sheet.
- Real winter efficiency. We looked beyond headline figures measured in warm weather and focused on how efficiently each unit runs at the 5°C to 10°C air temperatures typical of a Kent winter.
- Correct sizing for hot tubs. We favoured models with outputs suited to typical 1,000 to 1,500 litre hot tubs, plus options for small inflatable tubs and larger swim spas.
- Build quality and corrosion resistance. Every pick has a titanium heat exchanger, which stands up to the chlorine and bromine used in hot tub water.
- Noise. Many Kent gardens are close to neighbours, so we considered how quietly each unit runs once the water is warm.
- Running costs. We estimated monthly heating costs using current typical electricity prices to show the real savings over a standard electric heater.
- Warranty and parts support. We favoured brands with established UK and European distribution, so parts and support are easy to get hold of.
- Ease of installation and servicing. We considered how simply each unit connects to a hot tub’s pipework and electrics, and how easy it is for engineers to maintain.
- Value for money. We balanced upfront cost against long term savings for different types of owner, from families to holiday let landlords.
How to Choose the Best Air Source Heat Pump for a Hot Tub in Kent and the South East
Choosing the best air source heat pump for a hot tub in Kent and the South East comes down to matching the unit to your tub size, your usage and your garden. Here is our engineers’ buying guide.
Match the Output to Your Hot Tub Size
A heat pump’s output, measured in kilowatts (kW), decides how quickly it heats your water. As a guide, a 5 kW heat pump can raise the temperature of a 1,200 litre hot tub by roughly 3°C to 4°C an hour. Most standard four to six seat hot tubs suit a unit of around 5 to 9 kW, inflatable tubs can manage with 3 to 5 kW, and swim spas usually need 7 kW or more.
Choose an Inverter Model for Year Round Use
Inverter heat pumps speed up and slow down to match demand rather than switching fully on and off. That makes them quieter and more efficient once your tub is up to temperature. If you use your hot tub through winter, the higher upfront cost of an inverter model usually pays for itself in lower bills.
Check Cold Weather Performance
Kent and the South East are among the mildest parts of the UK, with average winter temperatures typically around 4°C to 6°C, but frosty nights are still common inland around Ashford, Headcorn and the Weald. Check the lowest outdoor temperature each model is designed to work at, and look at its efficiency figures at 7°C rather than only at 15°C or above.
Plan the Position and Noise
The heat pump needs good airflow, so leave space around the fan and avoid tucking it into a tight corner or under decking. Keep it away from bedroom windows, both yours and your neighbours’, and on a solid, level base. Quieter inverter models are worth paying extra for in close knit streets in Medway or Thanet.
Look for a Titanium Heat Exchanger
Hot tub water contains chlorine or bromine, which can corrode ordinary metal over time. A titanium heat exchanger resists this and helps the unit last longer, so it should be on your checklist for any model you consider.
Get the Electrics Right
Most hot tub heat pumps need a suitable outdoor electrical supply with RCD protection, and larger units need a dedicated circuit. Any new outdoor circuit should be installed by a qualified electrician and meet Part P of the Building Regulations. Factor this into your budget when comparing quotes.
Use a Good Cover and a Cheaper Tariff
An insulated, well fitting cover makes a huge difference, because most of a hot tub’s heat escapes from the water surface when it is uncovered. Pair your heat pump with a time of use tariff, such as Economy 7 or a smart tariff, and set it to heat mainly overnight when electricity is cheaper.
Think About Warranty and Local Support
Check the warranty length, whether it covers parts and labour, and whether there is UK based support. A local installer who can visit quickly, whether you are in Dover, Maidstone or Sevenoaks, makes a real difference if anything goes wrong.
Ready to Explore Ways to Reduce Your Hot Tub and Home Heating Costs?
If you want to make your hot tub more economical to run or reduce your household heating bills, Guscott Heating can help you explore your options. Request a free online heat pump estimate to discuss suitable heating solutions for your property and understand the potential costs of installing an air source heat pump for your home.
If you are replacing a gas or oil boiler, our team can also explain how the £7,500 Boiler Upgrade Scheme grant could reduce your installation costs, subject to eligibility.
Request your free online heat pump estimate from Guscott Heating today and explore the right heating solution for your property.
Guscott Heating provides expert air source heat pump installation across Kent and the wider South East of England, helping homeowners and landlords find heating solutions suited to their properties.
Whether you want to make your home more energy efficient or improve the heating setup in a holiday let, our team is here to help you understand your options.
Frequently Asked Questions
There are a few other things you should know about hot tub heat pumps before you buy. Here are short answers to five questions Kent and South East hot tub owners often ask us.
Do I Need Planning Permission for a Hot Tub Heat Pump?
You usually do not need planning permission for a hot tub heat pump, because these units are small and normally count as garden equipment. However, if you live in a listed building or a conservation area, such as parts of central Canterbury, Faversham or Sandwich, check with your local council before installing any outdoor equipment.
Can My Home’s Air Source Heat Pump Also Heat My Hot Tub?
Your home’s air source heat pump is not normally used to heat a hot tub. Home heat pumps are designed and sized for radiators and hot water, and connecting a hot tub can affect their efficiency and warranty. A separate, dedicated hot tub heat pump is simpler, cheaper to run and easier to control.
How Long Does a Heat Pump Take to Heat a Hot Tub From Cold?
A heat pump typically takes around 6 to 12 hours to heat a standard 1,200 litre hot tub from cold to 38°C, depending on its output, the outside temperature and whether the cover is on. Heating it from cold takes around 39 kWh of heat, so a 5 kW unit needs roughly eight hours in mild weather.
Should I Keep My Hot Tub’s Built In Heater?
You should keep your hot tub’s built in heater, because it acts as a useful backup and frost protection. Most owners set the heat pump to do the everyday heating and set the built in heater to a slightly lower temperature, so it only switches on if the heat pump cannot keep up on the coldest days.
How Long Does a Hot Tub Heat Pump Last?
A hot tub heat pump typically lasts around 8 to 12 years with regular care. Keep the fan and fins free of leaves and debris, check the water chemistry regularly and have the unit checked once a year to help it reach the top of that range.
