Before you turn the heating on in Spain, there’s one cleaning job you shouldn’t skip

Households across Spain are about to switch on radiators that have sat unused since spring, and any dust that’s built up between the fins can get in the way of the heat. Clearing it can take as little as 10 minutes, though it’s a different job from bleeding the radiator.

Dust between the fins can hold the heat back

Dust that settles inside and behind a radiator over the warmer months doesn’t just sit there. On convector radiators (the type with thin metal fins between the panels), a layer of it can stop the heat escaping properly, according to heating supplier BestHeating. Checkatrade heating expert Aaron Willcox goes further and estimates that a very dusty radiator can lose 10 to 20 per cent of its efficiency. That’s one expert’s estimate rather than a measured result, but it’s still a good reason to give your radiators a quick clean.

It matters especially in Spain, where gas boilers feeding radiators heat more than 30 per cent of homes, according to figures by INE, the National Statistics Institute.

How to clear it with the radiator cold

Start with the heating off and the radiator completely cold, which is safer than tackling a hot one. Lay a towel on the floor underneath to catch whatever comes out. Then you’ve got a few easy options. A hairdryer pointed into the grooves along the top will blow the dust out, a vacuum with a thin crevice nozzle will pick it up, and a long-handled brush will reach what’s left behind. BestHeating even suggests wrapping a cloth around a ruler and sliding it between the panels.

Finish by wiping the outside with soapy water, then drying it straight away so it doesn’t rust. Willcox says doing every radiator in a home is only a 10-minute job.

Electric radiators need a lighter touch

Not every radiator in Spain is water-filled, though. If yours is electric, never take the panels off to clean them, as BestHeating advises, and stick to wiping the outside.

Bleeding is a separate job from cleaning

Dusting does nothing about the air trapped inside a water-filled radiator. That’s what bleeding is for, and Spanish consumer group OCU’s guidance is also to do it with the heating off and the system fully cold, which means waiting around two to four hours after switching it off, or right away if you’ve been enjoying the long summer temperatures across most of Spain and haven’t needed to turn on the heating until now. 

Open the small valve at the top (a screwdriver may be needed) with a container underneath, let the air escape until only steady water flows, then check the boiler pressure sits between 1 and 1.5 bar. Radiators with automatic bleed valves do it themselves.

So before the first properly cold evening, switch the heating off, wait for the radiators to cool and give them a few minutes with a brush and a towel.