An annual sweep keeps most chimneys in good shape. But there are times when a chimney needs attention before the next scheduled visit. Soot can build faster than expected. Birds nest in spring. Liners crack. The first sign of trouble is rarely the fire itself — it’s one of the smaller signals below. If any of them sound familiar, take it seriously.

1. Smoke entering the room when you light a fire

The most obvious warning sign — and the one homeowners are most likely to put up with for far too long. If smoke is rolling out of the appliance and into the living room instead of going up the flue, the chimney is not drawing properly. The cause is almost always one of four things:

• A blocked flue (soot, debris, bird’s nest)
• A cold chimney that needs warming through
• Negative air pressure (extractor fans, sealed rooms)
• A structural issue with the flue itself

If the smoke issue persists after the first few minutes of a fire, it’s not a cold-chimney problem — book a sweep and an inspection.

2. A strong burning, tar or acrid smell

That heavy, slightly chemical tar smell — especially noticeable on warm or damp days when you’re not using the fire — is the smell of creosote. Creosote is the sticky, flammable residue that builds up inside flues that haven’t been swept, particularly with wood-burners. Once you can smell it strongly, the build-up is already significant. This is a chimney fire risk. A proper sweep removes it; left long enough, it requires more aggressive cleaning.

3. Soot or debris falling onto the hearth

Find a small pile of soot, mortar fragments, twigs or feathers on the hearth in the morning? Something is loose up the flue. It might be ordinary soot from a long-overdue sweep; it might be parging failing; it might be a bird’s nest collapsing from above. None of those are problems that improve on their own. Book an inspection.

4. The fire struggles to light or stay lit

A healthy chimney pulls air up. A blocked or partially blocked one can’t. If you find yourself fighting with the kindling, getting smoky starts, or watching the fire die down repeatedly even with good fuel, the flue isn’t drawing. The cause is usually soot build-up, sometimes a partial blockage from debris or an old nest.

This is more common in autumn — the first fires of the season after months of idle flue accumulating cobwebs, condensation residue, and the occasional adventurous bird. It’s also a classic sign that you skipped last year’s sweep.

5. Birds, nests or scratching sounds

Spring brings nesting season — particularly for jackdaws, which absolutely love unused chimneys. If you hear scratching, chirping, fluttering or scraping sounds from the chimney breast, you have visitors. A nest in a flue is a fire hazard and a complete blockage; lighting the fire underneath one is dangerous. In the UK, active nests are legally protected during the breeding season, so timing matters — we can advise on what’s allowed and when.

Once the season ends, the nest needs removing and a cowl fitting to stop next year’s pair moving back in. We carry stainless-steel anti-bird cowls suitable for North East weather.

6. Black staining on the wall above the appliance

Look at the wall just above the fireplace or stove. Faint black soot marks, or staining that appears to be creeping outwards over time, is a sign that smoke is escaping from the appliance. The cause might be a damaged register plate, a worn door seal on a stove, a cracked flue, or simply a flue too full of soot to draw properly. Either way: book a sweep and inspection.

7. Your carbon monoxide alarm triggers

The most serious sign on the list. Treat it as an emergency.

If your CO alarm goes off:

1. Get everyone out of the room or property into fresh air.
2. Don’t use the appliance again until it’s checked.
3. If anyone has symptoms (headache, dizziness, nausea, confusion), call NHS 111 immediately. If symptoms are severe, call 999.
4. Once the alarm has cleared and ventilated, call a HETAS-certified sweep and an appliance engineer.

If you don’t have a CO alarm yet, get one. Battery-powered, fitted near the appliance, replaced every few years. They cost around £20 and they save lives.

Bonus: a season since the last sweep

Not a sign as such, but worth mentioning: if it’s been more than 12 months, you’re overdue regardless of how the fire is behaving. More on annual sweep schedules here.

North East context: salt air and old housing stock

Homes across Sunderland, South Shields, Tynemouth, Whitley Bay, Seaham and the wider North East coast deal with conditions that can accelerate flue problems. Salt-damp parging fails earlier. Driving rain works under cowls and flaunching. Older Victorian terraces in Newcastle, Gateshead and Sunderland often have shared stacks where one neighbour’s issue becomes another’s. More on the specific quirks of North East chimneys.

The short version: if you’re in a coastal or older property and you’ve spotted one of the signs above, don’t wait until autumn. Get it looked at now.

Quick summary

• Smoke in the room? Flue isn’t drawing. Book a sweep.
• Tar smell? Creosote build-up. Fire risk.
• Falling soot or debris? Something is loose up there. Inspect.
• Fire struggles to light? Likely soot or partial blockage.
• Scratching sounds? Nesting bird. Sweep + cowl.
• Black staining above the appliance? Smoke is leaking. Investigate.
• CO alarm triggered? Emergency. Out, then call for help.

If any of this sounds like your fireplace, don’t leave it. Book online in 30 seconds or WhatsApp us for urgent appointments.