How to choose a hot tub in the UK: four decisions that actually matter

Most buying guides spend five paragraphs telling you what a hot tub is before getting to the part you actually need. We're going straight to the four decisions that determine which model is right for you — size, jets, power supply and running costs — because everything else is secondary.

1. Size: how many people will actually use it?

Hot tub seating capacity is often optimistic. A '6-person' hot tub with six moulded seats will fit six adults, but none of them will be comfortable. A realistic guide: buy for two seats more than your usual group size so everyone has elbow room.

For a couple or family of three, a 4–5 person model is the sweet spot. For regular entertaining — groups of 4–6 — buy a 6-person model or consider a larger round wood-fired tub. Footprint matters too: most 5-person square electric tubs need a 220–240cm square space, plus 50cm clearance on at least two sides for servicing.

2. Jets: how important is hydrotherapy to you?

Jets range from 20 in basic models to 129+ in premium spas. More jets isn't always better — jet placement and direction determine the therapeutic effect. A model with 30 well-positioned jets targeting the lower back and shoulders delivers a better hydrotherapy session than 80 jets scattered randomly.

If hydrotherapy and jet massage are a core reason for buying, look at the Platinum Spas Arum (129 jets) or the Bari (32-amp, high-pressure). If you primarily want relaxation and socialising rather than therapeutic jet work, a simpler model or a wood-fired tub with basic water circulation is perfectly adequate.

3. Power supply: 13-amp plug-in vs 32-amp hard-wired vs wood-fired

13-amp plug-in: Some smaller hot tubs run from a standard domestic socket. Convenient for temporary use, but limited heating power means slower warm-up and inability to heat and run jets simultaneously at full power. Check the specification carefully — true plug-and-play hot tubs are limited in performance.

32-amp hard-wired: The standard for quality electric hot tubs including the Platinum Spas Bari, Trident Lite and Arum. Requires a qualified electrician to install a dedicated circuit from the consumer unit — budget £300–£600 for this work. Installation is subject to Part P building regulations. Plan this before ordering.

Wood-fired: Zero electricity requirement. The Amber Fully Loaded, Nordic Glow and Halo Ignite all heat entirely from a wood-burning stove — internal or external. Ideal for off-grid gardens, areas without easy electrical access, or buyers who prefer the ritual of fire-heating. Heat-up time is 1.5–2 hours. No jets in wood-fired models (water circulates by convection or with an optional pump).

4. Running costs: the decision most buyers underestimate

At 28p/kWh — the current UK unit rate — a hot tub using 3–5 kWh per day to maintain 38°C costs £307–£511 per year. This is for a well-insulated model with the cover on. Poorly insulated models, or tubs left uncovered, can use double this.

The single most impactful upgrade for running costs is an air source heat pump. A heat pump doesn't generate heat — it moves it from the air into the water, achieving a COP (coefficient of performance) of 3–5, meaning £1 of electricity delivers £3–£5 of heat. At COP 4, a tub that costs £511/year to run with a standard heater drops to approximately £128/year. We stock the Aquark Mr Silence in 7kW and 11kW if this appeals.

Wood-fired hot tubs have no electricity running costs. Wood fuel cost for a 2m tub is approximately £5–£10 per session using kiln-dried hardwood.

Hot tub comparison: all active models side by side

Running costs based on 28p/kWh UK electricity rate, 3–5 kWh/day average for electric models with cover in use. Individual usage patterns will vary.

Product spotlights

Hot tub running cost calculator: what will yours actually cost?

Running costs vary more than most buyers expect. The variables that matter: insulation quality, target temperature, frequency of use, ambient temperature, and whether you use a heat pump. Here is how to build your own estimate at the current UK rate of 28p/kWh.

The heat pump case: an Aquark Mr Silence 11kW heat pump costs £2,499. If it reduces your annual running cost from £409 to £102, that's a £307 annual saving. Payback period: approximately 8 years. If you plan to own the tub for 10+ years, a heat pump almost always pays for itself.

Installation requirements: what you need before delivery day

Installation is where most first-time buyers get caught out. Sort these four things before your hot tub arrives and delivery day will be smooth. Neglect any of them and you'll be waiting weeks.

1. The base

Every hot tub requires a solid, flat, level base capable of supporting its filled weight. A 5-person hot tub filled with water weighs 1,500–2,500kg — a standard timber decking or paving slab on sand is often inadequate. Your options:

• Concrete slab (recommended): minimum 100mm thick reinforced concrete. Suitable for any hot tub in our range. Cost: £500–£1,500 installed depending on size and access.
• Existing concrete or flagstone on concrete sub-base: suitable if the sub-base is intact and level. Have it checked before delivery.
• Purpose-built hot tub pads: interlocking plastic grid systems rated for the weight. More expensive than concrete but can be installed without groundwork. Check the rating for your specific model.

Level is non-negotiable. A hot tub on a surface with more than 5mm of variance over 2m will not seal correctly, will stress the shell, and will void most warranties.

2. Electrical supply

For 32-amp electric hot tubs (all Platinum Spas and Nuovo Adore models): a qualified electrician must install a dedicated 32-amp RCD-protected circuit from your consumer unit to the tub location. This work must comply with BS 7671 and be notified under Part P building regulations.

The cable run, trench (if buried), weatherproof socket and commissioning typically costs £300–£600, more for long runs or where groundwork is required. Book your electrician before ordering the tub — good electricians in the UK are typically 2–4 weeks out.

Wood-fired models (Amber, Nordic Glow, Halo Ignite) require no electrical supply unless you order the optional electrical add-on for lighting or circulation pump.

3. Water supply and drainage

A 5-person hot tub holds approximately 1,000–1,500 litres of water. Filling takes 30–60 minutes from a standard garden hose. You do not need a dedicated water supply, but you will need:

• A nearby outdoor tap with sufficient flow to reach the tub location
• Drainage access for the quarterly water change — typically a drain, soakaway or driveway where the water can safely discharge. Note: hot tub water treated with bromine or chlorine should not discharge directly into a watercourse or onto a lawn. Let treated water sit 24–48 hours before draining or use a neutraliser.

4. Access for delivery

Most 5-person hot tubs measure 200–230cm and weigh 200–350kg empty. They cannot be carried around tight corners or through standard 80cm doorways. Measure your access route from the delivery point to the final position before ordering. If access is restricted, discuss with us before purchase — some models can be tipped on their side temporarily; others cannot.

Frequently asked questions