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400mm Wide Horizontal Radiators

We have 17 horizontal radiators 400mm wide in stock from Ethiant, Reina and Carisa, from 400mm to 750mm high, priced from £85.38 to £273.79 with heat outputs from 889 to 2,930 BTU/hr (ΔT50).

Width is what a radiator has to fit; height and panel depth are what give it output. If the wall only allows 400mm, go taller or choose a double-panel model rather than settling for less heat. Every model is in stock for free delivery to mainland England and Wales, and each product page shows the certified heat output for every size so you can match it to your room with our BTU calculator.

400mm Wide Horizontal Radiators in stock

Compare every 400mm wide horizontal radiator in stock

Model Finishes Sizes in this group Heat output (BTU/hr, ΔT50) From
Traditional 2 Column Horizontal Radiators 500 Height White 500 × 425mm 1,126 £85.38
Ethiant Horizontal Single Flat Panel Radiator 600 Anthracite 600 × 420mm 1,542 £86.40
Traditional 2 Column Horizontal Radiator 600mm Height Black, White 600 × 425mm 1,328 £86.40
Neva Horizontal Mild Steel Radiator Anthracite, White 550 × 413mm 927–1,483 £90.04
Traditional 3 Column Horizontal Radiators 500 Height White 500 × 425mm 1,552 £104
Traditional 3 Column Horizontal Radiators 400 Height White 400 × 425mm 1,258 £104.83
Traditional 3 Column Horizontal Radiator 600mm Height Black, White 600 × 425mm 1,833 £112.32
Traditional 4 Column Horizontal Radiators 400 Height White 400 × 425mm 1,583 £112.32
Rione Single Mild Steel Radiator Horizontal White 544 × 400mm 889 £115.13
Traditional 3 Column Horizontal Radiators 750 Height White 750 × 425mm 2,292 £124.80
Traditional 4 Column Horizontal Radiators 500 Height White 500 × 425mm 1,979 £124.80
Traditional 4 Column Horizontal Radiators 600 Height White 600 × 425mm 2,344 £164.32
Slimline Horizontal Mild Steel Radiator Anthracite, White 600 × 400mm 1,068 £177.12
Traditional 4 Column Horizontal Radiators 750 Height White 750 × 425mm 2,930 £185.64
Rione Double Mild Steel Radiator Horizontal White 544 × 400mm 1,352 £181.55
Carisa Plata Horizontal Aluminium Designer Radiator Textured Anthracite, Textured White 600 × 420mm 1,179 £226.92
Carisa Plata Double Horizontal Aluminium Designer Radiator Textured Anthracite, Textured White 600 × 420mm 1,632 £273.79

Questions about 400mm wide horizontal radiators

How much heat does a 400mm wide horizontal radiator give out?

Between 889 and 2,930 BTU/hr at ΔT50 across the 17 models on this page. The highest output here is the Traditional 4 Column Horizontal Radiators 750 Height at 2,930 BTU/hr (859 W). All figures are the manufacturers’ certified outputs to EN 442, quoted at ΔT50 — the UK standard for sizing central-heating radiators.

Which 400mm wide horizontal radiator is the best value for heat?

On heat per pound it is the Traditional 3 Column Horizontal Radiators 750 Height: 2,292 BTU/hr for £124.80, about 18 BTU for every £1. The cheapest model on the page starts at £85.38.

What size room will it heat?

It depends on the model — the range on this page runs from a cloakroom, en-suite or small box room at 889 BTU/hr up to a bedroom, home office or small kitchen at 2,930 BTU/hr. A well-insulated modern room needs far less than an older one with single glazing and an outside wall, so use our BTU calculator with your room’s measurements before you choose.

What colours and finishes are available?

In this group we have 16 in white, 5 in anthracite, 2 in black. Colour is chosen as a finish option on the product page.

What else do I need to fit it?

A pair of radiator valves (a thermostatic set is the usual choice) — see our valves and accessories. Wall brackets are supplied with every radiator, and column radiators in this group can be fitted with feet where the wall will not take the full weight. Delivery to mainland England and Wales is free.

Related sizes and ranges

450mm Wide Horizontal Radiators · 500 x 400mm Horizontal Radiators · 600 x 400mm Horizontal Radiators

Back to Radiators by size.