Cleaning a Radiator: How to Do It Properly (Before Mould Takes Hold)

An avalanche starts with a snowball, and a damp-riddled house starts with a speck of dust or a fleck of rust. So prevent a growing avalanche of costs by reading our guide on how to clean a radiator - and clean ANY radiator, in fact.

All it takes is a sponge, a stick, and several minutes with some music playing.

Why Does My Radiator Get So Dusty?

You won't see this in the Instagram pictures of gorgeous interiors, but radiators get dusty quickly. This is because, when your clean radiators heat the air, that hot air rises; and when hot air rises, cold air rushes to fill the space where the hot air used to be; pulling in all that dust, hair, and other particles with it. This means your radiator is essentially a big hoover/vacuum.

Why Do I Need to Clean My Radiator?

Every room has a calculable BTU rating, which is the amount of heat output that it needs to be sufficiently heated. If the output of your radiator drops too much, then you won't just feel uncomfortable. Your home will begin to accumulate moisture. Moisture that is being allowed to cool to a liquid state.

It's unlikely that collected alone will cause your home to be riddled with mould, but if you have a build up of filth inside your radiator then you risk inviting a damp problem that will only get worse. So you need to know how to clean a radiator.

Hidden Filth: How to Flush Your Radiator

Old radiators need flushing, obviously, but even new radiators might have sucked up a clump of rust from your central heating systems. Cold spots and higher heating costs are the unfortunate result. And, like a tumour, these small lumps move can break apart and spread the issue throughout your plumbing. Not good.

Check out our article on flushing your radiator to clear out any corrosive sludge to learn how to clean a radiator on the inside. For cleaning the exterior of your radiator, keep reading.

How to Clean a Radiator

What you need

  • Vacuum / hoover
  • Something long and brush-like to clean with (duster, radiator cleaning brush, etc)
  • A bucket of hot water and a sponge (for the last step)
  • Washing up liquid/dish soap
  • An old towel, bedsheet, or dust sheet
  • (optional) general kitchen/bathroom cleaner spray

TIP: If you're stuck for a long brush and only have a standard floor brush simply sellotape or tie a cloth around the other end of the handle.

How to clean a radiator


  • Turn off your heating
  • Spray any stains with cleaner and wipe after 5 minutes
  • Vacuum under the radiator to collect any dust (even though more will fall, but it's  still a good idea to get as much of it as possible - lest it get kicked up and spread).


  • Vacuum as much of the radiator as possible using the hose extension of your hoover
  • Swap to your brush and clean as much of the back of your radiator as possible
  • If you have convector fins, it's especially important to get in between them and clear the dust because you won't be able to wash these areas with water (unless you put down a lot of towels).


  • Mix some washing up liquid inside your bucket of hot water until it's sufficiently foamy (which is usually just a foaming agent for visual effect, bit of marketing trivia there)
  • Dunk your sponge and wring out excess water until damp
  • Wipe down the outside of your radiator, pipework, and valves
  • If you live in a home with smokers or moulting pets, then the heat of your radiator can sometimes cause the smoke, dirt, and hair to stick to your walls. If so, you can wash the walls with the same sponge and soapy water.

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