Cold plunge installation checklist (UK): before it arrives, on the day, and the first week

Most cold plunge problems start before the tub is out of the box: it will not fit through the side gate, the only socket is on the wrong side of the garden, or nobody thought about where 450 litres of water goes on a Sunday afternoon. Work through this list before you order, and again when the delivery date is booked.

Updated 26 September 2026: the heaviest empty weight corrected to 220 kg; the Chill Tubs Pro's stated weight had been missed.

Before you buy

Measure the route, not just the space. Measure every door, gate, corner and step between the kerb and where the tub will live. Inflatables, pods and separate chillers come in boxes that fit anywhere. All-in-ones and stainless or cedar tubs do not: in our catalogue they are typically 700 to 1,000 mm wide and 1.7 to 2.2 metres long, and the heaviest state 125 to 220 kg empty. Check whether the maker allows the tub to be tipped on its side for access.

Check the delivery terms. Kerbside delivery means the driver leaves it at the kerb. Ask how many people you will need, whether there is a paid "place of choice" option, and what happens if it will not fit.

Decide where the chiller goes. A separate chiller sits on the ground beside the tub, with two hoses running to it. It needs airflow around its vents (follow the clearance in its manual), shade if you can manage it, and a spot where its hum will not keep you or a neighbour awake. Our running costs guide shows what shade saves.

The base

Water weighs a kilo a litre. A 450 litre tub holds 450 kg of water before you add the tub, the chiller and a person, and a two-person tub can pass a tonne. That load sits on a small footprint.

• Paving slabs or concrete on a proper sub-base are the safe default.
• Decking is fine only if it was built for the load. Ask whoever built it, or a builder, before you put a full tub on it.
• The base must be level, or the water line and the lid will not sit right and an inflatable's seams take uneven strain.
• Under an inflatable, add a floor protector so grit cannot wear through (the accessories guide has one).

Power

• A 13 A socket is enough for most units; check the manual, as a few large all-in-ones ask for 16 A.
• Outdoors, the socket must be weatherproof and on an RCD-protected circuit.
• A new outdoor circuit in England and Wales is notifiable under Part P of the Building Regulations. Book a registered electrician early: this is the step most likely to delay a first plunge.
• No extension reels, and nothing on the ground where it can sit in a puddle.

The safety guide covers who should speak to a doctor first and the rules for using the tub.

Water in, water out

Filling from a garden hose takes a while; do it the day before if the chiller has to pull the water down from tap temperature (our figures put that at under £1 of electricity for a 450 litre tub). Draining takes longer. Before the first fill, decide where the water goes: onto a lawn or beds if it is untreated, to a foul drain if you use chlorine or another sanitiser, following the product's label. A tub with a drain tap and a length of hose to the right spot turns a job of an hour into ten minutes.

Lids, children and pets

Keep the lid on whenever nobody is in the tub. It keeps the water clean and cold, and it stops a small child or a dog falling in. If there are children at home or next door, choose a lid that straps down or locks.

The first week

• Check every hose connection after the first day and again after the first week; fittings settle and drip.
• Rinse the filter after the first few days, when it catches the dust from the fill.
• Put a floating thermometer in the water and compare it with the chiller's display.
• Note the chiller's settings and the date of the fill. Most owners change the water every four to eight weeks with good filtration.

Winter

UK tap water is cold enough to plunge in for much of the winter. If a separate chiller or its hoses could freeze, follow the maker's winter instructions: some heat pumps are rated to run in sub-zero air, and some compressor chillers need draining or bringing inside. Keep the lid on; it keeps frost and leaves out.

How heavy is a full cold plunge?

Water weighs a kilo a litre, so a 450 litre tub holds 450 kg of water before the tub, the chiller and you. All-in-ones add their own weight on top; Plungepedia's catalogue lists empty weights of up to 220 kg (the Chill Tubs Pro) where the maker states one. Put it on a level, solid base, and ask whoever built a deck whether it can take the load.

Will a cold plunge fit through my door?

Inflatables and pods arrive in boxes. Most all-in-ones in our catalogue are 700 to 1,000 mm wide and 1.7 to 2.2 m long, so measure every door, gate and turn on the route, and check whether the tub can be tipped on its side. Kerbside delivery means you move it from the kerb.

Where do I drain a cold plunge?

Plan it before delivery. A 450 litre tub takes a while to empty through a garden hose. Untreated water can go on a lawn or beds; if you use chlorine or another sanitiser, check the product label and your water company's advice before draining it anywhere other than a foul drain.