The best 80 litre hot water cylinders, compared.
Top pick: TESY 80 litre BiLight vertical – Highest listing score in this set, with 4.4 from 72 reviews and class C, if you will read the data plate. Best value: Eldom Spectra 80 litre – About £189.00, with a stated 2 kW element, a stated safety valve and 4.3 from 39 reviews. Updated 21.10.2026.
An 80 litre hot water cylinder is a wall-mounted electric storage heater of about 80 litres, not an indirect copper cylinder on a gas boiler. You use it for a flat or a one-bathroom home that can wait about two hours for a full reheat on a 2 kW element. Only two have a star line, and several cards disagree on wattage, energy class, orientation or what is in the box. How to read the contradictions is in the [80 litre buying guide](/hub/hot-water/80-litre-hot-water-cylinder/sub/80-litre-hot-water-cylinder-buying-guide). Cold water sits in the vessel, an immersion element heats it, and you draw it off later. It is not the indirect copper cylinder a gas boiler heats through a coil, and none of these five amazon.co.uk listings shows a coil. You look at this size for a flat or a one-bathroom home on electric heating, where showers do not overlap. That figure is a rule of thumb for the element size, not a stopwatch test of these five units.
An 80 litre hot water cylinder is a wall-mounted electric storage heater of about 80 litres, not an indirect copper cylinder on a gas boiler.
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Personal buying guide
Question 1 of 2
What space do you have?
The TESY 80 litre BiLight vertical is listed at £234.99 on amazon.co.uk, with 4.4 from 72 reviews, as an unvented wall store in energy class C. The shell is given as 44 × 50 cm with a depth of 440 mm and a weight of 24 kg, which is a short height for an 80 litre vertical tank, so measure the space against the data plate rather than the title alone. A UK review says the parcel arrived with no fittings and no cable, which matches an included-components line that only says cylinder. The wattage field prints 1,500 kW and the heat-output field prints 65°C, so neither figure is a usable element rating. One review on the same ASIN describes a 100 litre unit drawing about 2.5 kW, which means the 72-review file is not a clean sample of this volume. The card states a two-year warranty and a 220 V corded supply, and it does not name a BS 1363 plug or who may install it. It has the largest star line in this set, though 72 reviews sit under a 100-review floor.
Pros
Cons
Best for: You want the only sizeable UK review file in this set and you will read the data plate before an installer starts.
Less suitable: You need a stated element in kilowatts, a valve in the box, or a review sample that is only this 80 litre model.
Specifications
Common questions
What does the TESY 80 litre box contain?
The included-components line says cylinder. A UK review says the parcel had no fittings and no cable.
What element size does the card state?
The wattage field prints 1,500 kW and the heat-output field prints 65°C. Neither is a usable element rating. A review on the same ASIN describes a 100 litre unit at about 2.5 kW.
Does the listing say who may install it?
The listing asks whether professional installation is needed and does not answer. No BS 1363 plug is stated.
The Eldom Spectra 80 litre is listed at £189.00 with 4.3 from 39 reviews and a stated element of 2 kW at 230 V. The title says vertical and a mechanical thermostat, while the dimensions read 82.5 cm wide by 45.7 cm high by 457 mm deep, which is a landscape shell, and the bullets claim a TFT display, timers and MyELDOM. Energy class is C on the attribute line and B in a bullet. Maximum pressure is 7 bar on the attribute line and 8 bar in a bullet, and the attribute maximum temperature is 40°C. A safety valve is stated, and the bullets also mention a cable and plug, though BS 1363 is not named. Two review bodies are marked United Kingdom: one says it heats reasonably quickly, and one says it is not fit for purpose. The other bodies in the file are marked Germany, so they are not a UK install record. Weight is 22.7 kg, the country-of-origin line says Bulgaria, and a mixed-water bullet says about 120 litres at 37°C.
Pros
Cons
Best for: You want a lower shelf price with a stated valve, and you will treat orientation and the class letter as unsettled until the plate arrives.
Less suitable: You need the app, the energy class, or the mounting direction to agree on the same card.
Specifications
Common questions
Does the Eldom include a safety valve?
Yes. The title, the bullets and the special-features line all state a safety valve. The bullets also mention a cable and plug.
Is it vertical?
The title says vertical. The item dimensions are 82.5 cm wide by 45.7 cm high by 457 mm deep, which is a landscape shell.
What do the reviews say about UK use?
The star line is 4.3 from 39. Two bodies are marked United Kingdom: one says it heats reasonably quickly, and one says it is not fit for purpose. The other bodies in the file are marked Germany.
The TESY BiLight 80 litre Wi-Fi is listed at £249.99, the highest shelf price in this set, with class B on the card, a digital panel, a 24/7 timer and the MyTesy app. Heat output is printed as 2 kW and a bullet says 2,000 W, while a separate wattage field prints 220 watts, so you cannot quote one element until the data plate is in your hand. The included line is a wall bracket, and the bullets say fixing bolts and screws are not included. Maximum pressure is 8 bar, supply is 230 V, and the maximum temperature is 70°C. Dimensions are 44 × 90 cm, a depth bullet prints 455 m, and the weight line prints 85 kg. Part number 306344 matches a UK retailer row at the same £249.99, but that retailer table is not this Amazon card, and the listing file has no star line. A flow field of 20 litres per minute is not heated recovery from a 2 kW element.
Pros
Cons
Best for: You want the Wi-Fi timer and the part number a UK retailer also lists, and you will buy the valve and the bolts separately.
Less suitable: You need reviews, one wattage figure, or a complete unvented kit in the box.
Specifications
Common questions
Can you control this TESY from a phone?
The bullets say yes. Temperature and a 24/7 timer are controlled in the MyTesy app, and the card also lists a digital panel.
What power does the listing state?
Heat output is 2 kW and a bullet says rated power 2,000 W. A separate wattage field prints 220 watts. A flow field prints 20 litres per minute, which is not heated recovery from a 2 kW element.
Are the fixing bolts in the box?
The included line says wall bracket. The bullets say fixing bolts and screws are not included.
The TESY BiLight 80 litre horizontal is listed at £229.99 as an unvented wall shell, 86 × 47 cm and 22 kg, with 3 kW at 220 V and energy class C on the card. The model number GCH 80 44 20 B12 TSR is printed, the maximum temperature is 60°C, and the maximum pressure is 6 bar. The included line is the cylinder only, and the card names a 3 bar temperature-and-pressure valve and a 1.5 mm cable as items you still need. Bullets claim a two-year warranty, up to three people, and 24 minutes of hot water between reheats. Those occupancy and runtime lines are the seller’s sentences, not a draw-off test of this unit. Plumbing is described as 15 mm compression with one cold inlet and one hot outlet. There is no star line and no BS 1363 plug, and the listing asks who may install it without answering. A UK retailer table for a horizontal BiLight 80 lists 2,000 W rather than 3 kW, so treat the Amazon element figure as a printed claim until the data plate is checked.
Pros
Cons
Best for: Cupboard or loft height forces a horizontal 80 litre shell, and you will supply the valve and cable through the installer.
Less suitable: You want a vertical store, a review sample, or a kit that arrives complete.
Specifications
Common questions
Does the horizontal TESY include a safety valve?
No. The included line says cylinder only, and it names a 3 bar temperature-and-pressure relief valve and a 1.5 mm electrical cable as items you still need.
Can it be installed outdoors?
The listing asks that question and does not answer it. The style line says horizontal wall mounted.
What energy class is printed?
The attribute table says C. The bullets also claim a piston effect and 24 minutes of hot water between reheats for up to three people. Those lines are seller claims, not a test.
The Thermex Digital 80 litre Wi-Fi is the lowest shelf price in the listing files at £177.10, listed as a vertical store at 2 kW and 230 V with energy class B. The included line lists the heater, a manual whose English is not guaranteed, a 3-way safety valve and a wall anchor. Maximum pressure is 8 bar, maximum temperature is 75°C, weight is 23 kg, and the lining is stainless steel with an electronic anode that the card says does not need replacement. Wi-Fi, a smart programme and legionella protection are stated. Depth is 460 mm, while width and height are not given. There is no star line in the listing file. A bullet says installation needs no permission from the network operator, which is not a UK competent-person line or a Part P exemption. The spare-parts line says 10 years of EU availability, and no BS 1363 plug is stated.
Pros
Cons
Best for: You want the cheapest card that states a valve and a 2 kW element, and you can accept a listing with no reviews.
Less suitable: You need a UK review sample, a guaranteed English manual, or a complete height and width before you order.
Specifications
Common questions
How long does the Thermex take to heat?
The listing asks and does not answer. The card states 2 kW, 230 V and a maximum temperature of 75°C. A full reheat on a 2 kW element is a wait of about two hours, as a rule of thumb, not a timed test of this unit.
Is a safety valve included?
Yes. The included line lists a 3-way safety valve and a wall anchor, plus a manual whose English is not guaranteed.
Does the listing say you can fit it without an installer?
A bullet says installation needs no permission from the network operator and that the unit is not a high-voltage heater. It does not name a UK competent-person scheme or a BS 1363 plug.
Five amazon.co.uk listings are kept. The score uses the star line and review count, whether the element, energy class, orientation and included parts agree, the shelf price against what the box contains, and UK-marked review text only. There is no lab test. A missing star line counts as no customer sample. Reviews marked Germany are not treated as UK installs. Weights sum to 100. The highest score is the top pick. Best value is a different listing: a lower shelf price that still states an element, a safety valve and a star line.
Amazon star line
30%Stars and the review count come from the amazon.co.uk file for that ASIN. A missing star line scores as no customer sample. Fewer than 100 reviews cuts the score. The plain TESY is 4.4 from 72. The Eldom is 4.3 from 39. The other three have no star line.
Card agreement
30%The element, the energy class, the orientation and the included parts should agree between the bullets and the attribute table. A wattage field that cannot be an element, such as 1,500 kW or 220 watts beside 2 kW, cuts the score. A class letter or a mounting direction that the same page contradicts also cuts it.
Price against the box
20%Shelf price in GBP is read against what the listing actually puts in the box. A lower price with a stated valve scores higher here than a higher price whose card omits the valve, the cable or the fixing bolts. Price alone, with no star line, does not decide best value.
UK review text
20%Only UK-marked review text counts as install evidence. A review that names a different volume cuts the sample. German-marked Eldom reviews are not treated as UK installs. A star average is not a draw-off test.
An 80 litre electric store is a small vessel for a flat or one bathroom, not a family cylinder on a boiler. The decision is whether the card agrees with itself. Read the element, the class letter on the attribute line, the orientation against the dimensions, and the included line before you compare shelf prices. A star line under 100 reviews is a weak sample. This is not a lab test, and a seller sentence about three people is not a draw-off result.
An 80 litre hot water cylinder in this comparison is a wall-mounted electric storage heater. Cold water sits in the vessel, an immersion element heats it, and you draw it off later. It is not the indirect copper cylinder a gas boiler heats through a coil, and none of these five amazon.co.uk listings shows a coil. You look at this size for a flat or a one-bathroom home on electric heating, where showers do not overlap. On a 2 kW element a full reheat is a wait of about two hours.
These five are direct electric stores. None shows a boiler coil. If the job is an indirect vessel on a gas boiler, this category is the wrong product.
1,500 kW, 220 W beside 2 kW, and 20 litres per minute are not usable element ratings. Quote a wattage only when the card prints one figure. A 20 litres per minute line is not heated recovery from a 2 kW element.
Most written Eldom reviews in the file are marked Germany. They are not evidence of a UK install. A review that names a 100 litre unit does not describe this 80 litre shell.
Quote a wattage only when the card does not print a second figure. The plain TESY vertical shows 1,500 kW, which cannot be an element, and a heat-output field of 65°C. The Wi-Fi TESY shows 2 kW and a 2,000 W bullet, then a wattage field of 220 watts. A 20 litres per minute flow on that listing is not heated recovery from a 2 kW element. The horizontal TESY shows 3 kW as one field. The Eldom and the Thermex both state 2 kW. Use the class letter on the attribute line.
Over 15 litres, an unvented store in England and Wales is notifiable under Approved Document G unless a competent-person installer self-certifies. The wall has to carry about 80 kg of water plus the shell. Discharge has to be visible and safe, with a metal pipe to a vertical tundish. Two independent safety devices plus a thermostat are part of that arrangement. Scotland and Northern Ireland use their own standards.
Three typical situations, each with a recommendation from this comparison.
You heat water with electricity, showers do not overlap, and you can wait for a reheat. The TESY 80 litre BiLight vertical is the top pick if you want the largest star line in this set and you will read the data plate. The wattage field on that card is not usable.
The ceiling will not take a tall vertical tank. The TESY BiLight 80 litre horizontal is the shell that states 86 × 47 cm. The box is the cylinder only, so the installer still needs the valve and the cable the card names.
You want a stated safety valve without paying the top of this set. The Eldom Spectra 80 litre is best value at about £189.00, with 2 kW stated and 4.3 from 39 reviews. Treat orientation and the class letter as unsettled until the plate arrives.
The top pick is the TESY 80 litre BiLight vertical at about £234.99. It has the highest listing score in this set, with 4.4 from 72 reviews and class C on the card. That file is under 100 reviews and mixes in another size, so the data plate still has to match the advert. Best value is the Eldom Spectra 80 litre at about £189.00, with a stated 2 kW element, a stated safety valve and 4.3 from 39 reviews. Skip the TESY if you need one wattage figure and a valve in the box. Skip the Eldom if the mounting direction and the class letter have to agree on the same card.
TESY 80 litre BiLight vertical
Highest listing score in this set, with 4.4 from 72 reviews and class C, if you will read the data plate.
Eldom Spectra 80 litre
About £189.00, with a stated 2 kW element, a stated safety valve and 4.3 from 39 reviews.
Editorial
Peter F. is the editor for DIY & tools at productscompared.co.uk. Comparisons in this category are checked against amazon.co.uk listings, review evidence and public UK sources.
Guides on what to look for, how to use a product, and common mistakes.
Public UK sources named below. amazon.co.uk prices, stars and review counts on these five listings were taken from the listing files read on 20 October 2026. Page updated 21 October 2026.
This page contains affiliate links to amazon.co.uk (tag pcuk26-21). If you buy through them, we may earn a commission at no extra cost to you. Prices, stars and review counts are taken from those listings. We did not run a lab test.
