Placing heat reflector foil behind radiators can make rooms feel warmer by reflecting heat back into the space, and the material costs around £8, according to consumer group Which?.
The tip is particularly effective on external walls, where heat would otherwise escape into the brickwork or outside air. Which? shared the advice on its official TikTok channel, demonstrating how to "maximise your heat" and noting that the foil "allows the heat to be reflected back into the room" and is "particularly effective on external walls".
How the hack works
Radiator heat reflector foil is "padded and usually has an adhesive backing", making it "really easy to install", Which? said. The item is often sold for around £8.
While some people use standard kitchen tin foil as a cheaper alternative, Which? does not advise this. Ordinary kitchen foil can present a fire risk over time and deteriorates rapidly when exposed to the continuous, elevated temperatures of a radiator, creating a danger of smouldering or ignition. Kitchen foil is also thin, creases readily and lacks the insulation backing needed for genuine effectiveness.
Where reflector foil works best
Reflector panels should only be placed on radiators fixed to uninsulated external walls, which face the outside. This stops heat from escaping into the brickwork or outside air.
There is no benefit to putting foil on internal walls between rooms, as any heat absorbed by an internal wall stays inside the home anyway. If a home already has modern cavity wall insulation or foil-backed plasterboard, radiator panels will not make a noticeable difference.
Public reaction
In comments on the Which? video, one person said they had been "doing this for years" and that others should "definitely try it" because it is a great hack. Another asked whether it "really works", and someone responded: "Yes, how much depends on a few factors, like how much insulation is in the wall".
