Independent radiator and heating advice for UK homes
Almost every radiator guide in the UK is published by someone who sells radiators. Heatroom doesn't. No products, no commission, no affiliate links — just the numbers, with the sources shown.
Start with the calculator below, or jump to whatever brought you here.
Manufacturers quote radiator output at ΔT50. Look for a radiator rated at or just above this figure.
Estimate for guidance only. For a heat pump or a new heating system you need a full room-by-room heat loss calculation to BS EN 12831 carried out by a qualified engineer.
Radiator calculators
Four tools covering sizing, heat loss and unit conversion. All of them show their working, and all of them state the ΔT they assume — which most UK calculators quietly leave out.
Radiator problems
Leaks, cold radiators and heating that won't come on. Each guide starts with how to work out what's actually wrong, then what you can fix yourself and what needs a professional.
Radiator guides
Choosing between panel, column and vertical radiators, what it costs to move one, and how the whole circuit actually works.
Why Heatroom
Every figure on this site is checked against a primary source — Stelrad and Myson output tables, BS EN 442 test conditions, CIBSE design temperatures — and the source is named on the page.
The calculators state their assumptions, including the ΔT they work to. That single number changes a radiator's output by half, and it's routinely left unmentioned.
Heatroom sells nothing and has no commercial relationship with any manufacturer or installer. It's run by one person, and there's a name on it.