Guides · Heating
Towel rail types and sizing compared
Straight ladder, curved and electric-only towel rails compared using the outputs Wickes publishes, and why those watt and BTU figures are not one test and not a room heat-loss calculation.
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Heated towel rails explains central heating, electric and dual fuel, and why a plumbed rail is cold in summer. This page compares types and the size and output figures Wickes publishes. We have not tested a rail. There is no single official BTU figure for a bathroom. Radiator sizing makes the same point for panel radiators: a published output is a rough check, not a room-by-room heat-loss calculation.
Three types, three different numbers
| Listing | Type | Size Wickes states | Output Wickes states | How that output is described |
|---|---|---|---|---|
| K-Rad chrome straight ladder | Central heating | 800 mm high by 400 mm wide. Pipe centres 355 mm | 322 W and 1100 BTU/h | The features we read do not state a test condition |
| Balterley chrome curved | Central heating, curved ladder | Width 500 mm. The product details we read do not state a height | 710 BTU | Delta T50, mean temperature of 70° (75-65-20), as Wickes writes it |
| Kudox chrome electric | Electric only. Not connected to the heating | 800 mm high by 500 mm wide | 200 W | The element rating in the title and the specification. Not a Delta T50 output |
Do not line 322 W up against 200 W and call one "bigger". One is a heating output with no stated test on the features list. The other is an electric element rating. The curved rail publishes BTU at Delta T50 and does not publish a watt figure in the details we read. We have not converted BTU to watts.
The Horton and the smaller Kudox plumbed rail already on the towel rail guide are further examples, with their own outputs. Use this table for the type and the test condition, and that guide for how a plumbed rail is connected.
Straight, curved, electric
Straight ladder. Bars in one plane. The K-Rad listing is a chrome mild-steel ladder with 22mm tubes, brackets included, and a maximum working pressure of 7 bar. That 7 bar is Wickes's figure for this rail, not a pressure to set the heating to. Valves are a separate choice: see TRV options and radiator valves.
Curved. The front of the rail bows out, which can leave more room for a towel. The Balterley listing is chrome steel, 1/2in BSP tappings, valves sold separately, width 500 mm. Because the height is not in the product details we read, measure the wall and check the height on the page before you order. Wickes says the BTU figure is at Delta T50. It also says the rail can take a heating element to make it electric. Fitting that element is electrical work, covered below.
Electric only. The Kudox rail is not a plumbed radiator. Wickes lists 200 W, an IP55 rating, brackets, a prefilled rail and a 1 metre cable. A cable in the listing is not an instruction to wire it. In a bathroom the connection is for a qualified electrician. We do not give wiring instructions. In England, electrical work in homes falls under Part P, and some of it has to be notified. Approved Document P explains when. In Wales, Scotland and Northern Ireland, check the rules where you live.
A plumbed rail only heats when the heating is on. An electric rail can heat when the heating is off. Dual fuel, a plumbed rail plus an element, is explained on the towel rail guide. Anything that opens a gas boiler is for a Gas Safe registered engineer.
Using the output without inventing a size
Makers publish output so you can compare rails tested the same way. These three listings are not tested the same way, or at least Wickes does not say they are. If the rail is meant to be the only heat in the room, ask a heating engineer for a heat-loss calculation. A taller rail is not automatically enough, and towels hung on the rail block some of the heat. The towel rail guide says that too.
Pipe centres matter as much as the overall width. The K-Rad 400 mm rail lists centres of 355 mm. The curved rail lists centres of 464 mm against a stated width of 500 mm. If those centres do not match the pipes, the pipes have to move. That is the point where many jobs become a plumber's.
Rails at Wickes
We haven't tested this. Figures are as the maker states them (checked 13 November 2026).
K-Rad chrome straight towel radiator, 800 x 400 mm. A central heating ladder. Wickes lists 322 W and 1100 BTU/h, and does not state the test condition in the features we read. Brackets are included. Maximum working pressure is given as 7 bar.
Balterley chrome curved towel radiator, 500 mm wide. A curved central heating rail. Wickes lists 710 BTU at Delta T50 (75-65-20) and does not state the height in the product details we read. Valves are extra. Any electric element is for a qualified electrician.
Kudox chrome electric towel radiator, 200 W, 800 x 500 mm. An electric-only rail. Wickes lists 200 W, IP55, a prefilled rail and a 1 metre cable. Connecting it in a bathroom is work for a qualified electrician. We do not give wiring instructions.
Why can't I compare the watt figures?
Because they are not the same kind of number. The electric rail's 200 W is the element rating. The K-Rad's 322 W is a heating output with no test condition in the features we read. The curved rail gives 710 BTU at Delta T50 and no watt figure in those details. Compare like with like, or ask a heating engineer.
Does a bigger rail heat the bathroom?
Not by a rule of thumb we can cite. There is no official BTU-per-bathroom figure. Use the published output only as the maker states it, and see radiator sizing for why a calculator is not a heat-loss calculation.
Can I add an element to the curved rail myself?
Wickes says the curved rail can take an element. The electrical connection in a bathroom is for a qualified electrician, as is the electric-only rail above. Part P may apply. The plumbing side of a dual-fuel rail is covered in heated towel rails.