August 2026
Really happy with their products
They look modern and feel good quality. The price was competitive and delivery was prompt. Very pleased and will buy again.
AhmedPrompt delivery, competitive priceRead on Trustpilot
500 x 400mm Horizontal Radiators
Looking for a horizontal radiator around 500mm high and 400mm wide? We have 3 horizontal radiators in stock in this size from Ethiant, priced from £85.38 to £124.80 with heat outputs from 1,126 to 1,979 BTU/hr (ΔT50). Actual dimensions in this group run from 500–500mm high and 425–425mm wide; the exact size, pipe centres and output of each model are on its product page.
A 500 x 400 horizontal radiator is the size most UK homes were built around, so it usually replaces an existing radiator without moving the pipework, and the highest-output models here will heat a bedroom, home office or small kitchen. 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.
500 x 400mm Horizontal Radiators in stock
-
Traditional 2 Column Horizontal Radiators 500 Height
Price range: £85.38 through £228.60 Select options This product has multiple variants. The options may be chosen on the product page -
Traditional 3 Column Horizontal Radiators 500 Height
Price range: £104.00 through £312.00 Select options This product has multiple variants. The options may be chosen on the product page -
Traditional 4 Column Horizontal Radiators 500 Height
Price range: £124.80 through £372.32 Select options This product has multiple variants. The options may be chosen on the product page
Compare every 500 x 400mm 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 |
| Traditional 3 Column Horizontal Radiators 500 Height | White | 500 × 425mm | 1,552 | £104 |
| Traditional 4 Column Horizontal Radiators 500 Height | White | 500 × 425mm | 1,979 | £124.80 |
Questions about 500 x 400mm horizontal radiators
How much heat does a 500 x 400mm horizontal radiator give out?
Between 1,126 and 1,979 BTU/hr at ΔT50 across the 3 models on this page. The highest output here is the Traditional 4 Column Horizontal Radiators 500 Height at 1,979 BTU/hr (580 W). All figures are the manufacturers’ certified outputs to EN 442, quoted at ΔT50 — the UK standard for sizing central-heating radiators.
Which 500 x 400mm horizontal radiator is the best value for heat?
On heat per pound it is the Traditional 4 Column Horizontal Radiators 500 Height: 1,979 BTU/hr for £124.80, about 16 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 1,126 BTU/hr up to a bedroom, home office or small kitchen at 1,979 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 3 in white. 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
Back to Radiators by size.