How often should a chimney be swept?
Advice comes from HETAS, a government-authorised competent person scheme for solid fuel and biomass (GOV.UK), and the Scottish Fire and Rescue Service.
| Fuel | HETAS | Scottish Fire and Rescue Service |
|---|---|---|
| Wood | At least twice a year | Quarterly when in use |
| Smokeless fuel | At least once a year | Once a year |
| Bituminous coal or peat | – | Twice a year |
Sources: HETAS; Scottish Fire and Rescue Service. If you burn a mix of fuels, the fire service says to sweep at the highest frequency.
HETAS says the best times are just before the heating season starts and after the stove hasn't been used for a while, and that the second sweep should come after the peak of the heating season (HETAS).
What a sweep does
- Sweeps the flue and removes soot and tar deposits.
- Checks for blockages such as birds' nests, and can fit a bird guard or cowl.
- Can carry out a smoke test and give you a sweeping certificate for your records.
Carbon monoxide
Carbon monoxide has no colour or smell. Symptoms include headache, dizziness, feeling sick, tiredness and confusion, and they may ease when you go outside (NHS). In Scotland, a CO detector is required in any room with a carbon-fuelled appliance (Scottish Government).
Frequently asked questions
How often should I sweep a wood burner chimney?
HETAS says at least twice a year when burning wood. The Scottish Fire and Rescue Service says quarterly while it's in use.
Does a chimney need sweeping if I only burn smokeless fuel?
Yes, at least once a year according to HETAS and the Scottish Fire and Rescue Service.
What are the signs of carbon monoxide poisoning?
The NHS lists headache, dizziness, feeling sick, weakness, tiredness and confusion, chest pain and shortness of breath. If you suspect it, get fresh air, stop using the appliance and get medical help.