Placing heat reflector foil behind radiators can keep homes warmer and help reduce energy bills, according to consumer group Which?, but safety experts warn against using standard kitchen foil as a substitute.
As households switch on their heating for November, Which? has highlighted a simple way to maximise warmth without turning up the thermostat. The group says positioning heat reflector foil behind radiators "allows the heat to be reflected back into the room" and is "particularly effective on external walls".
How the hack works
Which? demonstrated the method on their official TikTok account, showing how to "maximise your heat". They noted that radiator heat reflector foil can be purchased for approximately £8 and is "padded and usually has an adhesive backing", making it "really easy to install".
Some people resort to tin foil as an economical option, though using ordinary kitchen tin foil behind a radiator is inadvisable as it can present a fire risk over time and deteriorates rapidly.
Safety warning on kitchen foil
While the trick has gained widespread popularity on social media for its heat-reflecting properties, safety specialists and fire service personnel warn that standard kitchen foil can oxidise and break down under the continuous, elevated temperatures of a radiator, creating a danger of smouldering or combustion.
Kitchen foil is also fragile, creases readily, and lacks the appropriate insulation backing to deliver genuine effectiveness.
Where reflector panels work best
Reflector panels should only be placed on radiators fixed to uninsulated external walls (walls facing the outside), as 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 won't make a noticeable difference.
Public reaction
In the comments on Which?'s post, one person mentioned they'd been "doing this for years" and that others should "definitely try it" because it's 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".
