Central heating radiators come down to three checks: output, size and how the unit sits on the wall. More panels or convector surface usually give you more heat from the same footprint, while single-panel options suit tighter spaces and lighter loads. If the pipework and wall space are fixed, dimensions matter as much as output - the wrong size is the one that causes the call-back.
Type 11 Single Radiator - 600 x 800mm White 2546 BTU
Type 11 single panel radiator 600 x 800 millimetres, 2546 Btu, white enamel
Stelrad Select Compact Type 11 Radiator - 750mm x 700mm
Compact Type 11 radiator 750mm x 700mm with 33mm pitch
Prorad Radiator Single Convector No11 - 400 x 1600mm 3696BTU
Prorad 400x1600mm single convector radiator, 3696BTU, white finish
Stelrad Compact K2 Radiator - 900mm x 800mm
Stelrad 900 x 800mm K2 radiator in white (RAL9016)
Halcyon Triple Panel Convector Radiator Type 33/K3 - 600mm x 1100mm
Triple panel convector radiator, 600mm x 1100mm, Type 33/K3.
Stelrad Halcyon Compact K2 Compact Double Panel Radiator - 400mm x 1400mm
Stelrad Halcyon K2 compact double panel radiator, 400x1400mm, 1763W, white, 15-y…
Stelrad Softline Compact K2 Double Panel Radiator - 700mm x 500mm
Stelrad Softline Compact K2 white double panel radiator 700mm x 500mm
Prorad Single Convector Radiator No11 - 600mm x 1400mm 4624 BTU
White type 11 compact radiator, 600mm x 1400mm, 4624 BTU, with 10-year guarantee
Stelrad K3 Compact Triple Panel Radiator - 700mm x 1100mm
Stelrad K3 compact triple panel radiator, white, 700 x 1100mm, Type 33
Type 22 Double Radiator - 600 x 500mm 3074 BTU
Type 22 double radiator 600 x 500mm, 3074 BTU, white enamel
For central heating radiators, start with the system and the job spec, not the finish. A standard wet system usually keeps you in the same family of product, but the real checks are output, depth, and whether the pipework and wall space will take the size you want. On a tight swap, a slimmer panel can be easier to land. If the room needs more heat, you may need a deeper unit or a larger footprint. The install package matters too. Flue route, filter requirement, fuel type, and who’s signing it off all change what you should be buying.
Flat panel central heating radiators are the usual pick when you want a straightforward swap and do not need much depth off the wall.
If you need more output from the same footprint, a double panel or double convector version gives you that. The trade-off is depth. It sits further out and can be tighter on pipe centres and clearance.
Single panel units are slimmer and easier to place where space is awkward, but you give up output. Once you have fixed the room layout, Radiators is where you step back and compare the wider range against the job.
The first check is output against space. A deeper unit gives you more capacity, but it also stands further off the wall and takes more room around pipework, skirting and furniture.
On a straight swap, that often matters more than the finish. For tighter spaces or lighter loads, a slimmer panel is usually the cleaner fit. Column Radiators suit jobs where the look is part of the brief and you can live with the extra depth. Designer Radiators come in when appearance is driving the choice, but you usually give up some simplicity and sometimes some output for that.
Once you’ve picked the unit, the next call is what sits around it. If the room needs a cleaner finish, radiator covers are the usual add-on, but they do reduce output a bit and make access tighter when you’re back for a valve change.
Radiator foil is worth considering on older external walls where you want heat back into the room rather than into the masonry. For a neater install, radiator valves and the right parts and accessories matter more than people think - it’s usually the small mismatches that slow you down on site.







