How Often Should You Sweep Your Chimney? (And How Long Does It Actually Take?)
How Often Should You Sweep Your Chimney? And How Long Does It Take?
Two of the questions we get asked most, and two that are surprisingly easy to get wrong. Here's a straight answer to both.
Most wood burners and open fires need sweeping at least once a year, and up to four times a year with heavy use. Coal needs at least two sweeps a year, and smokeless fuel, oil and gas at least one. A routine sweep takes 45 minutes to an hour, and adding a CCTV inspection takes another 20 to 30 minutes.
How often should you sweep your chimney?
These are the frequencies HETAS and most UK chimney professionals work to:
| Fuel or appliance | How often to sweep |
|---|---|
| Wood burners and multi-fuel stoves | At least once a year, and up to 4 times a year if you burn heavily through winter |
| Open fires burning wood | At least twice a year, ideally before the season and partway through |
| Bituminous coal | At least twice a year |
| Smokeless fuel | At least once a year |
| Oil-fired appliances | Once a year |
| Gas fires | Once a year. They produce far less soot, but the flue still needs checking |
The honest answer is that it depends more on how much you use your fire than on a fixed calendar rule. A stove lit most evenings through a cold winter builds up creosote and soot far faster than one used at weekends. If in doubt, book an extra sweep. Creosote build-up is one of the leading causes of chimney fires, and it's avoidable.
Not sure where your use falls? Our chimney sweep near me page has a full cost breakdown and FAQs.
How long does a chimney sweep take?
For a routine sweep with no major issues, most appointments take 45 minutes to an hour. That covers:
Protecting the room
Dust sheets down and the area around the fireplace covered.
Sweeping the flue
Brushes and a vacuum remove soot and creosote.
Inspection and smoke test
A visual check of the flue and appliance, then a smoke test to confirm the draw.
Clean-up
Everything left as we found it, with your certificate.
What can make it take longer
- Bird nests or heavy blockages need clearing carefully rather than just brushing through.
- A CCTV inspection, if you add one, usually takes another 20 to 30 minutes.
- Difficult access, like multiple flues or an awkward loft hatch.
We build our appointment slots with this in mind, so a routine sweep won't feel rushed. If we find something that needs a closer look, we'll explain it and talk through the options before doing any extra work.
What happens if you leave it too long?
Skipping a sweep doesn't cause an immediate problem, which is exactly why it's easy to put off. The risk builds quietly: creosote and soot accumulate, airflow gets restricted, and at worst a spark can ignite the deposits and start a chimney fire.
Carbon monoxide gives no warning. A dirty or blocked flue can push carbon monoxide back into the room instead of out through the chimney. Treat your sweep like an annual boiler service: routine, not optional.
Common questions
How often should you sweep your chimney?
Wood burners and open fires burning wood need sweeping at least once a year, and up to four times a year with heavy use. Bituminous coal needs at least two sweeps a year, and smokeless fuel, oil and gas at least one.
How long does a chimney sweep take?
Most routine sweeps take 45 minutes to an hour, including dust sheets, sweeping, a visual inspection, a smoke test and clean-up.
How long does a CCTV chimney inspection take?
A CCTV inspection usually adds 20 to 30 minutes to a standard sweep.
What happens if I don't sweep my chimney?
Soot and creosote build up, airflow gets restricted, and there's a risk of a chimney fire or carbon monoxide being pushed back into the room.
Related guides
Chimney sweep near me
Prices, what's included and FAQs.
What is creosote?
The three stages and how to prevent them.
Chimney services and prices
Sweeps from £95, CCTV, cowls and repairs.
Book a sweep in your area
Due your annual sweep?
We cover chimney sweeping across Essex and Hertfordshire. Every sweep includes a full inspection and clean-up as standard, and we can add a CCTV inspection or gutter clean while we're on site.