Most people in London switch the heating on for the first time in early October, and a lot of them notice the same thing. The heating smells burnt for the first hour or two. That’s months of dust cooking on the radiator. If you learn how to clean radiators properly before the heating goes on, you’ll stop the smell, cut the dust in the air and help each radiator heat the room a bit better.
It’s also a good time to think about waste. From 1 October 2026, the Ofgem energy price cap went up 4%, to £1,723 a year for a typical household. Gas is up 8%. Cleaning radiators won’t halve your bill, but there’s no point paying to heat a layer of fluff.
Why it’s worth cleaning radiators before winter
Most modern radiators have convector fins inside, the zigzag metal between the two panels. They’re there to pull cold air in at the bottom and push warm air out of the top. When dust packs into those fins, less air moves through, and the radiator warms the room more slowly.
Dust on a hot radiator also gets lifted into the air as the warm air rises. If anyone at home has asthma or a dust allergy, that’s usually when they start sneezing. It’s also why the heating smells burnt the first few times you use it. And in a small London flat with the windows shut, the dust has nowhere else to go.
So before you clean radiators, think about it as two jobs: the outside you can see, and the inside you can’t.
What you need to clean a radiator
- a vacuum cleaner with a crevice tool and a brush attachment
- a long, thin radiator brush (they cost a few pounds and bend to fit between the panels)
- an old towel or dust sheet for the floor
- a bucket of warm water with a little washing-up liquid
- two microfibre cloths, one damp and one dry
- a hairdryer (optional, but useful for the gap behind)
How to clean radiators step by step
1. Turn the heating off and let it cool
Never clean a radiator while it’s warm. Switch the heating off at the thermostat or turn the radiator valve to zero, and give it at least an hour. Cleaning a hot radiator with a damp cloth leaves streaks and can burn your hands.
2. Lay a towel on the floor
You’ll be surprised how much comes out. Put the towel or dust sheet right under the radiator and tuck it against the skirting board.
3. Take the top grille off, if there is one
Many double radiators have a slotted cover on top. It usually lifts off or unclips at the ends. With it off, you can see straight down into the fins, and it’s much easier to clean radiators of this type.
4. Vacuum from the top
Run the crevice tool along the top and down into the fins. Then use the brush attachment on the front panel and the pipes at each end.
5. Brush out the fins
Push the radiator brush down between the panels and work it up and down. The dust falls to the bottom. Vacuum it up from underneath as you go, so it doesn’t settle straight back in.
6. Clean behind the radiator
The gap between the radiator and the wall is where the worst dust sits. Slide the long brush down the back, or hold a hairdryer at the top on a cool setting and blow the dust downwards onto the towel. Then vacuum the towel and the floor.
7. Wipe the outside
Wipe the panels, pipes and valves with the damp cloth and soapy water. Dry everything with the second cloth, so you don’t leave water marks or give rust a start on any chipped paint.
8. Clean the wall and skirting behind it
The wall above a radiator often has a grey shadow on it. That’s dust carried up by warm air. A damp cloth usually lifts it. Clean the skirting board below while you’re down there.
How to clean radiators that are hard to reach
Column radiators, towel rails and designer panels each need a slightly different approach.
Column radiators (the traditional kind in a lot of Victorian and Edwardian London homes) have gaps between each column. A long, thin brush and the crevice tool reach most of it. Take your time, as each gap holds its own dust.
Towel rails in bathrooms collect limescale and soap splashes rather than dust. A cloth with a little diluted white vinegar clears it, but test a small hidden area first on chrome or coloured finishes.
Radiators behind furniture are the ones people skip. Pull the sofa or bed away at least once a year. Dust trapped there is often why the heating smells burnt in the living room. Furniture pressed against a radiator also blocks the warm air from reaching the room.
Other radiator jobs to do at the same time
Once you clean radiators, it takes ten more minutes to check they’re actually working well.
Bleed them if the top is cold. If a radiator is warm at the bottom and cold at the top once the heating is on, there’s trapped air. You’ll need a radiator key. Turn the heating off first, hold a cloth under the valve, turn it slowly until you hear hissing, and close it as soon as water appears. If you have a combi boiler, check the pressure gauge afterwards, as bleeding can drop it.
Don’t dry laundry on them. Wet clothes on a radiator block the heat and put a lot of moisture into the air. That’s one of the main reasons for condensation and black mould in London flats. We covered that in our guide to condensation and mould.
Keep curtains off them. Long curtains hanging over a radiator trap the heat behind the fabric and send it straight out through the window.
If you rent, tell your landlord in writing if a radiator doesn’t heat up at all, leaks or has a broken valve. Heating repairs are their job, not yours.
Why the heating smells burnt the first time you turn it on
That smell is almost always dust burning off the radiator or the boiler area after a summer of sitting still. It should fade within an hour or two. If you clean radiators before the first cold snap, you’ll mostly avoid the burnt smell.
A burning smell that’s strong, doesn’t go away, or smells like gas or plastic is different. Turn the heating off and get it looked at. For a suspected gas leak, open the windows, don’t use switches, leave the property and call the National Gas Emergency number on 0800 111 999.
When to let a cleaner do it
If you’ve got a whole house of radiators, some behind heavy furniture, it’s a long, dusty job. It fits well into a deep clean, where our cleaners work room by room and do the radiators, skirting boards, door frames and the spots behind furniture in one visit. You can ask for radiators specifically when you book.
If you already have regular cleaning, ask your cleaner to add a quick radiator dust once a month through winter. It stops the build-up from getting bad again. And if the dust is coming from old carpets, a carpet steam clean makes a big difference to how much ends up on the radiators in the first place.
For the rest of the house, our autumn cleaning checklist covers the other jobs worth doing before winter.
Radiator cleaning questions
How often should you clean radiators?
Give them a proper clean once a year, ideally in late September or early October before the heating goes on. That way the heating never smells burnt when you first switch it on. A quick dust of the top and front every few weeks through winter keeps them in good shape.
Does cleaning radiators make them more efficient?
Dust packed into the convector fins slows the airflow that carries heat into the room. Cleaning it out lets the radiator warm the room more easily. It won’t change your energy bill dramatically, but it stops you wasting heat.
What is the best tool to clean behind a radiator?
A long, flexible radiator brush is the easiest tool. A hairdryer on a cool setting also works well to blow dust down from behind onto a towel, which you can then vacuum.
Can I clean a radiator while the heating is on?
No. Turn the heating off and let the radiator cool completely first. Wiping a hot radiator can burn your hands and leaves streaks on the paint.
Why does the heating smell burnt when I turn it on?
Usually it’s dust burning off the radiators after the summer. It should fade within a couple of hours. If it smells of gas, leave the property and call 0800 111 999.
Want radiators, skirting boards and the dusty corners behind the furniture done in one go? Book a deep clean or ask us a question first.
