What a cold plunge costs to run in the UK (2026): every chiller, at the current price cap

Updated 23 September 2026: rebuilt around the new Ofgem price cap, the stated power draw of every UK chiller in our catalogue, and a model checked against the only metered UK figure.

Plungepedia's model puts a lidded, insulated 450 litre cold plunge held at 5C at £4 a month in a UK winter and £11 in summer sun, at the Ofgem price cap of 26.32p per kWh. Leave the same tub uninsulated and open and summer costs £46. The chiller you buy changes that far less than the lid and the tub do.

Written by Aodhan, who has run separate chillers on inflatable, hard-wall and rigid tubs over three years. Chiller figures are from the Plungepedia catalogue, read from each brand's own UK page and last checked on 5 October 2026. The unit rate is the Ofgem price cap average for direct debit, 1 October to 31 December 2026; use the rate on your own bill in the running cost calculator.

What it costs, by tub and season

A 450 litre tub held at 5C, at 26.32p per kWh, including 0.3 kWh a day for the pump and standby:

"Insulated" means an all-in-one, a rigid insulated shell or a hard-wall pod with an air gap. "Uninsulated" means an inflatable, a stock tank or a bare tub. Holding 3C rather than 5C adds roughly a tenth in summer; holding 8C takes off about a sixth.

Does the model hold up?

The only metered figure published in the UK comes from Cold Plunge Store, which put an energy meter on a 0.9 HP chiller for a month: about 1.2 kWh a day, holding a lidded, insulated 400 litre tub at 3C. Our model gives 1.2 kWh a day for the same tub on a 19C day. We set the pump and standby allowance from that reading, because no brand publishes what its pump draws; it is one meter on one setup, and we will replace it with more when more are published. Kaldera's own worked figures for its chillers (£15 to £35 a month, at an assumed two to four hours of running a day) sit between our insulated and uninsulated rows. The figures you will see quoted at £60 to £120 a month are American or assume a tub that is never covered.

Why the watts on the box mislead

Chillers are sold on watts, and brands quote three different ones: cooling output (the heat taken out of the water), input power (what comes out of your socket) and horsepower (the compressor). Only the second is on your bill, and the compressor only draws it while it is running. Once the water is cold it runs in short bursts to replace the heat leaking in through the walls and lid, so a 1,000 W chiller on a well-lidded tub can cost less to run than a 300 W one on an open tub.

The brands that state both cooling and input watts show how much heat a chiller moves for each watt it draws: 1.7 for Kove's Core, 2.4 for its Pro, 2.7 for Keico's Pro. That efficiency falls as the water gets colder; we use 1.5 at plunge temperatures.

Every UK chiller that publishes its power draw

Cost per hour is what the chiller costs for each hour the compressor runs, at 26.32p per kWh. It is not the daily cost: on a lidded, insulated 450 litre tub in a UK summer the compressor runs for about one to three hours a day, depending on its size.

The other chillers in our catalogue (see every UK chiller compared) do not publish an input figure. None of them publishes what the circulation pump draws, which matters because some pumps run all day for filtration. Our 0.3 kWh a day allowance is about £2.40 a month; a pump that draws 60 W around the clock would cost nearly five times that. If your chiller lets you set the pump to run on a timer, use it.

The first fill

Every time you change the water the chiller has to pull a fresh fill down from tap temperature. Taking 450 litres from 15C to 5C costs about 92p in electricity. With good filtration you change the water every four to eight weeks, so this adds pennies a month, not pounds.

Chiller or bagged ice?

Shop ice is 72p per kg (a 2 kg bag at Tesco, checked 23 September 2026). Ice has to cool the water, not just hold it, and a 450 litre tub from a 15C summer tap to 8C takes about 44 kg once you allow for the ice melting before you get in: about £32 a session. From a 12C spring tap it is about 25 kg, or £18. A chiller holding the same tub cold all month costs £9 to £37 in summer, so at two or more plunges a week in summer the chiller wins on running cost, and it wins on hassle from the first week. Two 2 kg bags, a common top-up, take 450 litres down by less than 1C, so in spring and autumn most of the cold in an ice bath comes from the tap, not the ice. Ice makes sense for a small tub, for occasional plunges, or in winter when the tap is already close to plunge temperature. The ice calculator works it out for your tub and your bag price.

What cuts the bill

• A lid. The biggest single saving: most heat enters through open water. Our accessories guide explains why most cheap "insulated" covers are not.
• Insulation. An insulated tub costs more up front and a fraction as much every summer month.
• Shade. A garage, or a north-facing wall, costs about a fifth less than full sun in summer.
• A warmer target. 8C costs about a sixth less to hold than 5C in summer.
• A clean filter. A clogged filter makes the pump and compressor work longer.
• Winter. From November to March the chiller barely runs outdoors; some owners switch it off and plunge at tap temperature.

Other running costs

Filter cartridges (£10 to £30 every one to three months; sizes and prices are in the accessories guide), sanitiser or ozone parts (a few pounds a month) and water. Budget £5 to £15 a month on top of electricity.

How much does a cold plunge cost to run per month in the UK?

For a 450 litre insulated tub with a lid, held at 5C, about £4 a month in winter and £9 to £11 in summer at the Ofgem price cap of 26.32p per kWh. The same tub uninsulated and left open costs £37 to £46 a month in summer. Add £5 to £15 a month for filters and sanitiser.

How much electricity does an ice bath chiller use?

Home chillers in the UK draw 280 to 1,800 W while the compressor runs, but they run in short cycles, so daily use depends on the tub, not the chiller: about 1.1 kWh a day for a lidded, insulated 450 litre tub in summer shade, and 4.6 kWh if it is uninsulated and uncovered.

Is a bigger chiller more expensive to run?

Not much. A bigger compressor draws more while it runs but pulls the water down faster and then rests. The heat leaking into the tub decides the bill; the chiller's size decides how quickly it recovers.

Is a chiller cheaper than buying ice?

For anyone plunging more than once or twice a week in summer, yes. Cooling a 450 litre tub from 15C to 8C takes about 44 kg of shop ice, about £32 a session at 72p per kg; a chiller holds the same tub cold for a month for less than one of those sessions.

Does a cover make a difference?

More than anything else you can change. On a 450 litre insulated tub in summer shade, taking the lid off and losing the insulation takes the bill from £9 to £37 a month.