Panel radiators

IN THIS GUIDE

What panel radiators are

Panel radiators are the standard plumbed radiator on UK central heating — flat steel panels with convector fins behind. They’re described by their make-up: Type 11 (single panel, single fin set), Type 21/P+ and Type 22 (K2) (double panel, double fins). More panels and fins mean more heat from the same width.

Heat output & sizing

Output is quoted in BTU or watts and needs to match your room’s heat loss — too small and it never warms up, too big and it wastes energy. A double-panel (Type 22) gives roughly double the output of a single (Type 11) the same size, handy where wall space is tight. Get the figure from the BTU calculator.

Type 11 vs 21 vs 22

Type 11: slimmest, lowest output — small rooms. Type 21 (P+): mid output. Type 22 (K2): deepest, highest output — the workhorse for living rooms and larger spaces. Deeper radiators stick out more but fit the needed output on a shorter wall.

Cost to buy & fit

Panel radiators are the best value output per £ — a standard white panel is often £40–£150, with fitting on an existing circuit around £100–£200 each. A brand-new radiator with fresh pipework costs more.

Best rooms

Almost every central-heating room — they’re the default for a reason. Choose single panels for small, low-loss rooms and doubles where you need more heat without a wider radiator.

Choosing the right panel

Work out the required output first, then pick the panel type that delivers it in the space you have. Add thermostatic radiator valves (TRVs) for per-room control, and consider a low-surface-temperature version for children’s rooms.