Replacing a radiator: 6 or 8 connections, which to choose?
In short
- A 6-connection radiator connects at the sides or underneath at the ends. An 8-connection radiator adds a central bottom connection, in ¾" Eurocone, with a fixed wall distance of 65 mm (source: Stelrad).
- To choose, look at where your pipes come from: at the side or under one end, 6 connections are enough; two pipes close together under the radiator, on the right, need 8 connections.
- At the same size, the 8-connection version costs 9 to 25% more on our Belrad models: €159.76 against €130.84 for a 600 x 1000 mm type 22.
When replacing a radiator, output is not the only question: the new one must also fit the existing pipes. Panel radiators come with 6 or 8 connections, and the difference is where the connections are. This guide explains how to identify your installation and which model to choose from the Belrad radiators in our range.
Last updated: October 2026. Prices recorded in the shop on 06/10/2026, VAT included.
What do “6 connections” and “8 connections” mean?
The number of connections is the number of ports available to connect the radiator. Only two are used, flow and return; the others are closed with blanking plugs. The more ports, the more options to match the existing pipes.
Belrad is the brand of a Belgian heating wholesaler, now part of Versa Group. Its 8-connection radiators are sold by other retailers as Stelrad Bel8 and share the outputs of the Stelrad Novello 8. Its 6-connection models state the same outputs as the Stelrad Novello. This is what Stelrad's technical documentation describes for these two ranges:
| 6 connections | 8 connections | |
|---|---|---|
| Side connections | 4 × ½" female | 4 × ½" female |
| Bottom connections | 2 × ½" female, at the ends | 4 × ¾" male Eurocone: 2 central and 2 at the ends |
| Central connection | no | yes, fixed wall distance of 65 mm |
| Built-in valve | preset, right-hand side, for M30 × 1.5 head | preset, right-hand side, for M30 × 1.5 head |
Stelrad notes that the bottom connections are used in pairs and cannot be combined with others: you use either the two central ports, the two end ports, or the side ports.
How do you know which connection you have today?
Look at where the two pipes of your current radiator come from:
- The pipes reach the sides of the radiator, top and bottom: that is a side connection. A 6-connection radiator fits.
- The pipes come from the floor or wall under both ends: that is a bottom connection at the ends. A 6-connection radiator also fits.
- The two pipes are close together, under the radiator, on the right: that is a central connection. You need 8 connections.
Also note the height, length and type of the old radiator from its label, and measure the centre distance between the two connections. With the same height and length, the connections of the new radiator should in principle line up with the old ones.
When to choose 6 connections?
A 6-connection radiator is the right choice when the pipes arrive at the side or under one end. It is also the cheapest model at the same size.
Our range includes 100 Belrad radiators with 6 connections, in type 22 (60 models, 578 W to 4,482 W, €64.61 to €325.76) and type 33 (40 models, 1,334 W to 4,778 W, €127.27 to €351.92).
When to choose 8 connections?
An 8-connection radiator is needed when the pipes come up in the middle, under the radiator. It also keeps the side and end connections, which makes it the most versatile model if you are unsure about your installation.
The central connection is ¾" Eurocone, with an H-block linking the radiator to pipes from the floor or wall. According to Stelrad, the distance between this central connection and the wall is fixed at 65 mm, so several radiators line up neatly. Types 22 and 33 can be turned around for a left-hand connection, but this wall distance then changes.
We offer 103 Belrad radiators with 8 connections, including 64 in type 22, from 747 W to 4,482 W and from €85.58 to €460.55.
What is the price difference between 6 and 8 connections?
At the same size and output, the 8-connection version costs 9 to 25% more on our Belrad radiators:
| Model | Output | 6 connections | 8 connections | Difference |
|---|---|---|---|---|
| T22 600 x 600 mm | 1,039 W | €85.98 | €97.47 | +13% |
| T22 600 x 1000 mm | 1,732 W | €130.84 | €159.76 | +22% |
| T22 600 x 1400 mm | 2,425 W | €175.69 | €192.56 | +10% |
| T22 900 x 1000 mm | 2,395 W | €176.99 | €193.52 | +9% |
| T33 600 x 1000 mm | 2,389 W | €187.97 | €228.79 | +22% |
| T33 600 x 1400 mm | 3,345 W | €252.60 | €314.71 | +25% |
If your pipes are at the side, 8 connections add nothing: choose 6 connections.
Which parts do you need for the connection?
The built-in valve on both models comes without a thermostatic head. You therefore need an M30 head, and for a central connection an H-block matching where your pipes come out. These parts are in our connection parts collection:
| Part | For | Price incl. VAT |
|---|---|---|
| Belrad M30 thermostatic head, white | 6 and 8 connections | €5.67 |
| ¾" Eurocone H-block, floor outlet | 8 connections, pipes from the floor | €6.84 |
| ¾" Eurocone H-block, wall outlet | 8 connections, pipes from the wall | €7.42 |
| Belrad M30 H-block kit, floor or wall | 8 connections | €22.11 |
| Eurocone 15 mm compression fittings (2 pieces) | with an H-block | €3.85 |
Replacing a radiator means draining the system, refilling it to pressure and bleeding the air. If you are not used to it, ask a heating installer.
Frequently asked questions about 6 and 8 connection radiators
What is the difference between a 6-connection and an 8-connection radiator?
An 8-connection radiator adds a central bottom connection, in ¾" Eurocone. A 6-connection radiator only connects at the sides or underneath at the ends.
Can a centrally connected radiator be replaced by a 6-connection one?
Not without changing the pipework. A 6-connection radiator has no central port: either move the pipes or choose an 8-connection model.
Does an 8-connection radiator give more heat?
No. At the same size and type, output is identical: 1,732 W for a 600 x 1000 mm type 22, with 6 or 8 connections. Only the connection options differ.
Is the thermostatic head included?
No. According to Stelrad, the built-in valve comes without a thermostatic head. It takes heads with an M30 × 1.5 thread, such as our Belrad M30 head at €5.67.
Do you need an installer to replace a radiator?
It is recommended. The system must be drained, the connections adapted, the installation brought back to pressure and bled. A mistake can cause a leak.
See radiators with 6 and 8 connections
Size, type and output are on every product page: see 6-connection radiators or see 8-connection radiators. Collection is at our shop in Schaerbeek.
Sources: Bati-Mat Shop range (prices incl. VAT recorded on 06/10/2026) · Stelrad, technical documentation “STR-TD-NL” (Novello and Novello 8 sheets, EN 442 heat output table) · Versa Group, “About us” (versagroup.be).