Hot water

Updated: 21.10.2026Hub page

Hot water covers instantaneous water heater with remote control, 18kW instantaneous water heater, 27kW instantaneous water heater, 50 litre hot water cylinder, 120 litre hot water cylinder and knob cylinder, and the other product types on the cards below. Each comparison says what that product is for, and which checks still apply when the listings change.

Once you have the product type, the comparison is where the current listings live. Shelf prices and makers stay there.

Hot water

Instantaneous water heater with remote control

Handset, basin unit or shower class

Seven instantaneous water heaters from about £46.99 to £344.99. Stiebel DCE-X is the top pick and states no handset. Mulcort LF-001 at about £46.99 is best value.

Comparison guides

18kW instantaneous water heater

400 V supply, review count, no plug-in

Three 18kW instantaneous water heaters on amazon.co.uk. Rheem RTEX-18 at about £364.17 is the top pick by review count. Bosch is the 400 V row. Best value is not named.

Comparison guides

24kW instantaneous water heater

Natural gas or LPG, one shower

Three 24kW gas instantaneous heaters from about £151.99 to £239.99. GASLAND GS318NG is the top pick. CAMPLUX GX318LP at about £239.99 is best value, the LPG row.

Comparison guides

27kW instantaneous water heater

Only one row is 400 V three-phase

Three 27kW instantaneous water heaters. Stiebel Eltron DHE 27 Set at about £821.57 is the only 400 V row and the top pick. Two cheaper listings are specified at 240 V.

Comparison guides

50 litre hot water cylinder

One-person store, class B or C

Four 50 litre cylinders from about £159.99 to £219.00. Eldom Favourite at about £189.35 is the top pick. TESY BiLight horizontal at about £159.99 is best value.

Comparison guides

80 litre hot water cylinder

Vertical store, wattage and the box

Five wall-mounted electric 80 litre cylinders from about £177.10 to £249.99. TESY BiLight vertical is the top pick. Eldom Spectra at about £189.00 is best value.

Comparison guides

Condensing boiler

Flow, layout and energy class

Twelve condensing boilers from about £951.54 to £5,437.54. Sime Vera HE 30 at about £980.61 is the top pick. Beretta Mynute X 25 C is best value. Eleven cards have no stars.

Comparison guides

Knob cylinder

Measured split, not a hot-water tank

Four knob cylinders from £6.55 to £13.99. GANZTECH 30/40T at about £10.99 is the top pick. BGS 45/45 is best value. None prints TS 007.

Comparison guides

11 kW electric shower

Comparison guides

21 kW instantaneous water heater

Comparison guides

Bosch tankless water heater

Comparison guides

Gas boiler

Comparison guides

Gas water heater

Comparison guides

Hot water cylinder

Comparison guides

Point-of-use water heater

Comparison guides

Sacrificial anode

Comparison guides

Stiebel Eltron water heater

Comparison guides

Tankless water heater

Comparison guides

Tankless water heater 3.5kW

Comparison guides

Thermoflow tankless water heater

Comparison guides

Water booster pump

Comparison guides

Water dispenser

Comparison guides

Water distributor

Comparison guides

Water feature pump

Comparison guides

Water lily

Comparison guides

Water softening system

Comparison guides

Water wall

Comparison guides

Hot water guides

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Buying guides that are already written sit under 18kW, 24kW and 27kW heaters, 30, 50, 80, 120 and 200 litre cylinders, condensing boilers, instantaneous water heaters with a remote, and knob cylinders.

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Common questions about hot water

What comparisons are on this hot water hub?

Eleven comparisons are live. Four cover instantaneous water heaters: a remote-control set of seven listings, an 18 kW set of three, a 24 kW gas set of three, and a 27 kW set of three. Five cover stored cylinders at 30, 50, 80, 120 and 200 litres. One covers twelve condensing boilers. One covers four knob cylinders, which are euro-profile door locks, not tanks. Each page uses amazon.co.uk listings. Products Compared did not run a laboratory test. A qualifying purchase can earn a commission at no extra cost to you.

Which instantaneous water heater is the top pick?

For a remote, the top pick is the Stiebel Eltron DCE-X 6/8 Premium at about £344.99, 4.2 from 25 reviews, and that card states no handset. Best value there is the Mulcort LF-001 at about £46.99. The 18 kW top pick is the Rheem RTEX-18 at about £364.17 by review count. The 27 kW top pick is the Stiebel Eltron DHE 27 Set at about £821.57, the only 400 V row. Those two pages do not name a best value.

Can I run an 18 kW or 27 kW heater from a UK socket?

No. None of the 18 kW listings is a 13 A plug-in. On a single-phase 230 V supply, 18 kW is about 78 A and 27 kW is about 117 A, outside a normal domestic cut-out. The Bosch Tronic 4000 18 EB at about £428.72 is the only 400 V row among the 18 kW listings. The Stiebel Eltron DHE 27 Set is the only 400 V row at 27 kW. Three-phase comes from the distribution network operator before that class can run.

Which hot water cylinder is on these pages?

Two 30 litre stores are the TESY BiLight at about £139.99 and the TTulpe Buono 30-O at about £149.00. Four 50 litre stores run from about £159.99 to £219.00, with the Eldom Favourite at about £189.35 as the top pick and the TESY BiLight horizontal at about £159.99 as best value. Five 80 litre stores run from about £177.10 to £249.99. The top pick is the TESY BiLight vertical at about £234.99, 4.4 from 72 reviews. One review text describes a 100 litre unit, so check the data plate. Best value is the Eldom Spectra at about £189.00. The only 120 litre listing is the TESY BiLight at about £254.99. The 200 litre listing is the Daikin Altherma M HW at about £1,888.76, a heat pump with no review line.

Which condensing boiler is the top pick?

Among twelve listings saved on 20 October 2026, from about £951.54 to about £5,437.54, the top pick is the Sime Vera HE 30 at about £980.61. It is the only card with a printed hot-water flow of 13.5 litres per minute, plus 30 kW and methane/LPG. Best value is the Beretta Mynute X 25 C at about £1,208.84. Eleven cards have no star rating. A score of 5.0 from two reviews, with no written text, is not a laboratory result.

Why is a knob cylinder on a hot water hub?

A knob cylinder is a euro-profile door cylinder with a key outside and a turn inside, also called a thumbturn. It is not a hot-water tank. Four amazon.co.uk listings from £6.55 to £13.99 were kept on 19 October 2026. None prints TS 007, Sold Secure or a Kitemark. The top pick is the GANZTECH 30/40T at about £10.99, 4.6 from 273 reviews, when the measured split matches the door. Best value is the BGS 45/45 at about £6.55.

Did you test these products in a lab?

No. Scores come from amazon.co.uk listing fields and the review lines on those pages. Stars and counts are the figures shown there. Prices are shelf prices in GBP at the capture date on each comparison, in October 2026. A small review sample is not treated as a strong verdict, and a missing review line is left with no count. This hub did not run a laboratory test and does not name a UK test winner.

Where should I start?

If you want hot water at one basin, open the remote-control comparison and read the size guide before the price. If the job is a shower on three-phase, open the 18 kW or 27 kW comparison and check 400 V first. A 24 kW gas heater is a different comparison, for natural gas or LPG, not a 13 A plug. If you are storing water, match 30, 50, 80, 120 or 200 litres to the listing that states that volume. A replacement boiler is the condensing boiler comparison. A thumbturn for a door is the knob cylinder comparison.