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.
Stelrad K3 Compact Triple Panel Radiator - 600mm x 600mm
Type 33 triple panel radiator 600 x 600mm in white
Revive Radiators Revive2 Double Panel Double Convector K2 Compact Radiator - 400…
K2 compact radiator, 400x800mm, 3439 Btu, 10-year guarantee.
Stelrad Softline Compact Type K1 Steel Panel Radiator 3343BTU - 600 x 1000mm
3343BTU steel panel radiator with curved grille, 600x1000mm
Stelrad Softline Compact Type K3 Steel Panel Radiator - 600 x 1400mm 11413Btu
Stelrad Softline K3 steel panel radiator, 600x1400mm, 11413Btu, white gloss
Stelrad Halcyon Compact K2 Double Panel Double Convector Radiator - 700mm x 1400…
White double panel double convector radiator, 700mm x 1400mm
Stelrad Compact K2 Double Panel Radiator - 600mm x 600mm
Compact white Type 22 radiator, 600 x 600mm
Kudox Premium Type 21 Steel Panel Radiator - 500 x 800mm 3139Btu
White Type 21 steel radiator, 500 x 800mm, 3139Btu
K-Rad Kompact Radiator Type 21 - 600X500MM
White Type 21 double panel convector radiator, 600x500mm
Stelrad LST Standard K2 Radiator - 650 x 1160mm
White Type 22 double panel LST radiator, 650 x 1160 millimetres
Prorad Radiator Double Panel No21 - 700mm x 800mm 4201BTU
Prorad double panel radiator 700x800mm, 879W/3000 BTU/h
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.







