Vertical radiator: sizes, heat output and connection
In short
- A vertical central heating radiator is usually 1.6 to 2 m tall and 40 to 70 cm wide. In our range, heat output goes from 924 W to 2,772 W.
- At the same size, a type 22 gives clearly more heat than a type 20: at 1800 x 500 mm, 1,845 W against 1,266 W, about 46% more.
- Prices in the shop range from €238 to €608 incl. VAT, with a 10-year manufacturer warranty on type 20 and 22.
A vertical radiator frees up wall width and heats a room with the same hot water as a standard radiator. Three criteria drive the choice: the available height, the heat output the room needs, and where the existing pipes are. This guide uses the real sizes and outputs of the 44 vertical radiators in our range.
Last updated: October 2026. Prices recorded in the shop on 20/10/2026, VAT included.
What sizes do vertical radiators come in?
Vertical central heating radiators usually come in three heights: 1,600, 1,800 and 2,000 mm. Width ranges from 400 to 700 mm. The wider the radiator, the more heat at the same height.
Before choosing, measure the free wall height, leaving space above the floor and below the ceiling, and check the room around the pipes. Under a low ceiling or below a window, a horizontal radiator is often simpler.
| Range | Heights | Widths | Heat output | Price incl. VAT |
|---|---|---|---|---|
| Type 20 flat white | 1,600 to 2,000 mm | 400 to 600 mm | 924 to 1,649 W | €245 to 344 |
| Type 20 flat matt black | 1,600 to 2,000 mm | 400 to 600 mm | 1,099 to 1,649 W | €238 to 468 |
| Type 22 Vertex flat white, Stelrad | 1,600 to 2,000 mm | 400 to 700 mm | 1,356 to 2,772 W | €375 to 603 |
| Type 22 Vertex flat white, Belrad | 1,800 to 2,000 mm | 500 to 600 mm | 1,708 to 2,218 W | €349 to 425 |
| Type 22 flat matt black | 1,800 to 2,000 mm | 500 to 600 mm | 1,845 to 2,376 W | €482 to 608 |
| Double oval and square | 1,800 mm | 472 to 608 mm | 1,640 to 2,164 W | €239 to 311 |
At the same size, the Vertex flat model sold under the Belrad name gives about 7% less heat output than the Stelrad Vertex Plan: 1,708 W against 1,845 W at 1800 x 500 mm, 2,049 W against 2,214 W at 1800 x 600 mm. It is also cheaper, from €349.
Which heat output for which size and type?
The output of a vertical radiator depends on its surface and its type. European standard EN 442 requires manufacturers to state output with water at 75 °C flow and 65 °C return in a 20 °C room, a difference called ΔT 50 (source: EN 442). With cooler water, for example from a heat pump, the radiator gives off less heat than the stated value.
These are the outputs of our white models at the same height and width, at ΔT 50 (source: Stelrad 2026 technical documentation, Vertex Plan range, EN 442 values at 75/65/20 °C). The type 22 column is the Stelrad Vertex Plan:
| Size (H x W) | Type 20 flat | Type 22 Vertex flat |
|---|---|---|
| 1600 x 400 mm | 924 W | 1,356 W |
| 1600 x 500 mm | 1,155 W | 1,695 W |
| 1800 x 400 mm | 1,013 W | 1,476 W |
| 1800 x 500 mm | 1,266 W | 1,845 W |
| 1800 x 600 mm | 1,519 W | 2,214 W |
| 2000 x 500 mm | 1,374 W | 1,980 W |
| 2000 x 600 mm | 1,649 W | 2,376 W |
How many watts your room needs depends on its size, insulation and windows. Work out the required output before choosing a model, and ask a heating installer if in doubt.
Type 20, type 22 or double: what is the difference?
The type describes how the radiator is built. For panel radiators, the first digit is the number of panels and the second the number of convector fin rows.
- Type 20 flat: two panels without fins. Slimmer and plainer, but less heat at the same size. A good choice when the required output is moderate.
- Type 22 Vertex flat: two panels and two fin rows. At 1800 x 500 mm, the Stelrad Vertex Plan type 22 states 1,845 W, against 1,266 W for a type 20 of the same size.
- Double oval or square: a radiator made of vertical elements. At 1,800 mm tall it states 1,640 W at 472 mm wide and 2,050 W at 590 mm, from €239.
Type 20 and 22 carry a 10-year manufacturer warranty, the double models 5 years, according to the product sheets.
How is a vertical radiator connected?
A vertical radiator is usually connected at the bottom, to the flow and return pipes. The key check is the centre distance between the two connections: if it does not match your pipes, the pipework must be adapted or a connection kit used.
Some models have a central connection, such as the square double radiator with central connection. For these we offer central connection kits, angled or straight, in white, black or chrome, from €35.53 to €44.44, plus a floor and wall set at €45.62.
Replacing a horizontal radiator with a vertical one is possible, but the water connections are almost never in the right place. Have an installer check the connection before buying.
What about an electric vertical radiator?
Without central heating, an electric vertical radiator avoids all pipework. The Stelrad Vertex Plan electric comes in 1800 x 500 mm at 1,250 W (€661.17) and 1800 x 600 mm at 1,500 W (€712.46). It runs on mains power: installation is simpler, but running costs depend on the electricity price.
White or matt black?
White remains the most common and offers the widest choice of sizes. Matt black is available in type 20 flat and type 22 flat, from €238 to €608.
Frequently asked questions about vertical radiators
What heat output does a vertical radiator need?
It depends on the room, not the radiator. First work out what the room needs, then choose a model whose output at ΔT 50 covers it. In our range, vertical central heating radiators go from 924 W to 2,772 W.
Does a vertical radiator heat less than a horizontal one?
No, at the same output it heats just as much. Only the stated output matters, and it depends on the surface and type (20, 22), not on orientation.
Which height should I choose?
The tallest that fits the wall. At the same width, a 2,000 mm model gives more heat than a 1,600 mm one: for a 500 mm wide type 22, 1,980 W against 1,695 W.
Can a horizontal radiator be replaced by a vertical one?
Yes, but the water connections usually need to be moved or extended. Check the centre distance and pipe position with an installer before buying.
What warranty comes with a vertical radiator?
According to our product sheets, 10 years for type 20 and 22 models and 5 years for double models.
See the vertical radiators
All 44 models mentioned are online, with height, width and output on each product page: see all vertical radiators. Collection is available at our shop in Schaerbeek.