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Is a 50 litre cylinder enough for a shower?

Updated: 21 October 2026

You want a shower, not a bath, and you are hoping a 50 litre store will cover one person. It can, if the head is modest and the tank is already hot. It will not cover a deep bath or two showers back to back without a wait. This page asks whether a 50 litre cylinder is enough for a shower, and it does not rank the four listings. That table is the [50 litre hot water cylinder comparison](/hub/hot-water/50-litre-hot-water-cylinder). Peter F. wrote these notes on 20 October 2026 from public UK sources and those listings. The minutes below are rules of thumb, not a lab shower. A qualifying amazon.co.uk purchase can earn a commission at no extra cost to you.

You want a shower, not a bath, and you are hoping a 50 litre store will cover one person. It can, if the head is modest and the tank is already hot.

Our top picks

Eldom Eldom Favourite 50 litre Wi-Fi

Best overall

Eldom Eldom Favourite 50 litre Wi-Fi
8.6/10about £189.35
View offer
Eldom Eldom Spectra 50 litre vertical

Rank 2

Eldom Eldom Spectra 50 litre vertical
7.8/10about £175.00
View offer
TESY TESY BiLight 50 litre horizontal

Best value

TESY TESY BiLight 50 litre horizontal
7.4/10about £159.99
View offer
On this page
  1. 1.What 50 litres can cover
  2. 2.Stored litres and mixed litres
  3. 3.Minutes, not a promise
  4. 4.When the second shower is a wait
  5. 5.When an electric shower is the other answer

What 50 litres can cover

Picture one person, one outlet, and a tank that is already hot. Ariston UK calls 45 to 50 litres enough for a shower, and 80 litres the step up when several showers follow. The Hot Water Association sizes stored hot water at about 35 to 45 litres per occupant. A bath at about 100 litres of water at 40 °C does not fit. Enough, here, means one shower with a limit.

Stored litres and mixed litres

Stored water and mixed water are different numbers. Water sitting in the tank at around 60 °C is hotter than the water that lands on you. At the shower you blend it with cold. The Hot Water Association's shower sketch is about 18 litres a minute at 40 °C, of which about 11 litres a minute is drawn from water stored at 60 °C. The tank therefore falls more slowly than the flow you feel. A manufacturer PDF from OSO treats a five-minute mains shower at up to 18 litres a minute as similar in mixed volume to a bath. That is why a lively head and a 50 litre store fall out with each other.
Eldom Eldom Favourite 50 litre Wi-Fi

Testsieger

Eldom Eldom Favourite 50 litre Wi-Fi
8.6/10about £189.35
View offer

Minutes, not a promise

Take the Hot Water Association's 11 litres a minute drawn from a 60 °C store. Fifty litres divided by 11 is about four and a half minutes of that draw. Plumbworld puts a low-flow shower at about 6 to 8 litres a minute and a standard head at about 12 to 15. If it is 12 to 15 litres a minute of mixed water, the shower shortens. The TESY BiLight bullets quote a V40 of 78 litres and about 13 minutes. V40 is mixed water at 40 °C, and it is not a figure you can copy onto the Eldom or GEESEN tanks. The Favourite fiche quotes 68 litres at 40 °C. A Spectra trade sheet quotes 73 litres. A hotter thermostat stores more usable heat, and it also raises the scald risk. It does not turn one tank into two showers.

When the second shower is a wait

The second shower is a waiting game at 1.5 kW or 2 kW, not at boiler speed. A rule of thumb from the sizing notes is about 105 minutes for a 45 °C rise at 1.5 kW, and about 79 minutes at 2 kW. If two people need showers before work, a 50 litre store is the wrong tool even when the first shower was fine. Ariston's sketch sends that household towards something nearer 80 litres, such as an 80 litre hot water cylinder.

When an electric shower is the other answer

An electric shower heats cold mains in the shower itself, which is how NICEIC describes it. It is not fed by the cylinder, so it does not empty your 50 litres. B&Q asks for about 1 bar and 8 litres a minute at the mains. Checkatrade's 6 to 8 litres a minute is the performance to picture, not a rainfall head. That shower needs its own circuit, and it is not one of the four cylinders here. If one short shower is the job, stay with 50 litres and choose the head to match. If the sums are already too tight, the buying guide is where you decide the size was wrong. Hanging the store is competent-person work once the tank is over 15 litres, which the installation page sets out.

Common questions

How many minutes is that?
A 6 to 8 litre-a-minute head stretches the tank. A 12 to 15 litre-a-minute head shortens it. The TESY listing's about 13 minutes belongs to its own V40 of 78 litres at 40 °C. Do not copy that sentence onto every 50 litre tank.
Does a hotter tank last longer?
A hotter store gives you more heat to mix with cold, so the same 50 litres can feed a shower for longer than a tank left at a lower setpoint. Raising the setpoint has a limit on the appliance and a scald limit at the tap. It does not double the tank.
What if two people shower?
The second person is waiting, or they are showering in water that has already been mixed down. If mornings are two showers, look at a larger cylinder, or at an electric shower that heats mains water on its own circuit and does not draw the tank down.
Can I fill a bath?
Not from 50 litres if you mean a normal bath. A shallow rinse in the bath is a different, smaller job and is still not what these sizing guides mean by a bath. For a bath, step up in capacity rather than hoping insulation will invent litres.
Would an electric shower avoid the limit?
Yes, in the sense that an electric shower heats cold mains in the unit and is not fed from the cylinder. You still need enough mains flow, and you need a proper electrical supply for the shower. It is a different product from the cylinders compared here.
How long until it heats again?
The TESY listing's own heat-up claim, 15 °C to 60 °C in 1 hour 18 minutes, is a bullet on that horizontal model. Do not copy it onto a 1.5 kW Spectra title. The 105 minutes at 1.5 kW and 79 minutes at 2 kW are rules of thumb for a 45 °C rise, not a gas-boiler recovery.

Related pages

Best 50 litre cylinder

50 litre hot water cylinder

50 litre hot water cylinder: checks before you buy

Horizontal or vertical: which 50 litre heater fits

How to install a 50 litre electric water heater safely

Sources

Public UK sources named below, as used for this comparison. amazon.co.uk prices, stars and review counts are the figures on the four listings in the product data. Page updated 21 October 2026.

  1. Approved Document G (2024 amendments) (retrieved 21 October 2026)
  2. HSE hot and cold water systems (retrieved 21 October 2026)
  3. CNC Building Control: hot water cylinder permission (retrieved 21 October 2026)
  4. BSI BS EN 12897:2016+A1:2020 (retrieved 21 October 2026)
  5. Regulation (EU) No 812/2013 on legislation.gov.uk (retrieved 21 October 2026)
  6. Hot Water Association: sizing a hot water cylinder (retrieved 21 October 2026)
  7. Approved Document P 2013 (retrieved 21 October 2026)
  8. IEC 60379:2023 electric storage water heater methods (retrieved 21 October 2026)