Chimney Draught Excluders: A Cheap Fix for Lancashire Fireplaces

An open, unused chimney lets as much warm air escape as leaving a small window wide open around the clock. For Lancashire homes with traditional fireplaces – and there are thousands across the terraces of East Lancashire, the semis of the Ribble Valley and the cottages of the Forest of Bowland – this is one of the easiest and cheapest energy savings available. A chimney draught excluder costs £15 to £40, takes five minutes to fit, and can save an estimated £50 to £100 per year on heating bills. No tools, no expertise, and no permanent changes to your fireplace needed.

Why Chimneys Waste So Much Heat

Chimneys work on the principle of convection. Hot air rises, and a chimney provides a direct channel from your heated living room to the cold outside. Even when there is no fire burning, warm air from your room continuously flows up the chimney and is replaced by cold air drawn in through gaps around windows and doors. This creates a constant draught that your boiler has to work against.

The rate of heat loss depends on the size of the chimney opening and the temperature difference between inside and outside. On a cold Lancashire winter evening with the heating on and outside temperatures near freezing, an open chimney can lose the equivalent of 1 to 2 kWh of heat per hour. Over a six-month heating season, that adds up to 1,500 to 3,000 kWh of wasted energy – costing £60 to £120 at current gas prices.

Many Lancashire homes have multiple chimneys. A typical Victorian terrace in Burnley or Darwen might have three or four fireplaces – one in each ground-floor room and one or two upstairs. Even if you use one fireplace occasionally, the others are silently haemorrhaging heat 24 hours a day throughout winter.

Types of Chimney Draught Excluder

Several products are available, each suited to different situations and budgets. Here are the main options:

Chimney balloons (also called chimney pillows) are inflatable plastic or rubber bladders that you push up into the chimney flue and inflate to create an airtight seal. They cost £15 to £30 depending on size. The most popular brand in the UK is the Chimney Balloon, which comes in multiple sizes to fit standard and larger flues. You inflate it using a small straw or tube, and it wedges in place against the chimney walls. To remove it, you simply deflate it. If you forget and light a fire, the balloon pops and shrinks away (a designed safety feature), though you will obviously need a replacement.

Chimney sheep are made from felted wool and shaped like thick, fluffy pads that push up into the chimney flue. They cost £20 to £40 and have the advantage of allowing a small amount of ventilation while blocking the main draught. This ventilation helps prevent damp and condensation issues that can occur in sealed chimneys, which is particularly relevant for Lancashire’s damp climate. They are reusable and last for years.

Chimney caps and cowls fit on top of the chimney pot outside and permanently reduce downdraught while maintaining some ventilation. These cost £30 to £100 plus fitting (£80 to £150 for a roofer to install). They are a good solution if you never use the fireplace and want a permanent fix. However, they do not seal the chimney as effectively as an internal excluder, so they save less energy.

Register plates are metal or board covers that seal the bottom of the chimney flue at the fireplace opening. These are the most effective at stopping heat loss but also the most permanent. They cost £40 to £80 and need to be cut to size, which may require a professional fit. A ventilation grill should be included to prevent damp.

How to Fit a Chimney Draught Excluder

Fitting a chimney balloon or sheep takes about five minutes and requires no tools. Here is the basic process:

First, if the chimney has been unused for a while, use a torch to look up the flue and check for bird nests, debris or damage. Lancashire chimneys frequently accumulate jackdaw nests (these birds love chimney pots across Pendle, Ribble Valley and the West Pennine Moors), and removing any blockage before fitting your excluder is sensible.

Sweep out any loose soot or debris from the fireplace opening. Lay down newspaper or a dust sheet to protect your carpet – Lancashire chimneys that have not been swept in years can release a fair amount of soot when disturbed.

For a chimney balloon: push the deflated balloon up into the flue until it sits just above the fireplace opening (about 30cm up). Inflate it using the tube provided until it fits snugly against the chimney walls on all sides. Tuck the inflation tube behind the balloon where it is hidden but accessible. Do not over-inflate – the balloon should be firm but not stretched tight.

For a chimney sheep: simply push it up into the flue until it wedges in place. The thick felted wool compresses against the chimney walls to form a seal. Adjust the position until it feels secure and the draught stops. Leave the handle hanging down so you can easily remove it.

Dealing With Damp and Ventilation

Completely sealing a chimney without any ventilation can cause condensation problems, especially in Lancashire’s damp climate. Moisture from the air inside the house rises up the chimney and, if it hits a cold surface in the sealed flue, condenses into water. Over time, this can cause damp patches on the chimney breast, staining on the wallpaper, and even salt crystallisation on the brickwork.

The simplest prevention is to allow a small amount of ventilation. Chimney sheep do this naturally because the wool is not completely airtight. Chimney balloons can be slightly under-inflated to allow a tiny gap. Register plates should include a small ventilation grill.

If you notice any damp patches on the chimney breast after fitting an excluder, remove it temporarily and check for condensation in the flue. A chimney cap on top (allowing air flow from outside) combined with an internal excluder (slowing warm air rising) is the best combination for preventing both draughts and damp.

What If You Still Use Your Fireplace Occasionally?

If you light fires on winter weekends or during Christmas but the fireplace is unused 90% of the time, removable excluders are perfect. A chimney balloon deflates in seconds and can be pulled out before you light a fire, then refitted afterwards. A chimney sheep lifts out in one movement. Both are designed for exactly this pattern of occasional use.

Remember to remove the excluder before lighting any fire. Setting fire to a chimney balloon is not dangerous (they are designed to shrink away from heat), but it will destroy the balloon and fill the room with an unpleasant smell. A chimney sheep exposed to flames will also be ruined, and burning wool does not smell good either.

For homes with wood-burning stoves that have a flue liner connected to the chimney pot, a draught excluder is not needed when the stove door is closed because the stove’s own air controls manage the draught. However, if your stove has an air vent that remains open even when not in use, fitting a magnetic stove pipe damper (£20 to £40) can reduce heat loss when the stove is cold.

Other Cheap Fixes for Draughty Lancashire Homes

While you are tackling chimney draughts, consider these other quick wins that cost under £50 and can be fitted in minutes:

• Letterbox draught excluder: £5 to £15, may save an estimated £10 to £20 per year
• Keyhole cover: £2 to £5 per keyhole
• Self-adhesive foam strips for window frames: £5 to £10 per window
• Draught-excluding brush strip for door bottoms: £5 to £15 per door
• Sash window draught-proofing strips: £10 to £30 per window (professional sash window draught-proofing costs £100 to £200 per window but is much more effective)

Combining chimney excluders with these simple measures can reduce overall draughts by 30% to 50% in a typical Lancashire terrace, saving an estimated £100 to £200 per year and making the home noticeably more comfortable.

How much can a chimney draught excluder save?

A single chimney draught excluder may save an estimated £30 to £60 per year per chimney on heating bills. A Lancashire terrace with three unused fireplaces could save an estimated £90 to £180 per year. Given that excluders cost £15 to £40, the payback period is measured in weeks rather than years. They are one of the best energy investments available.

Will blocking my chimney cause damp problems?

It can if you completely seal the chimney without any ventilation. The solution is to use products that allow a small amount of air movement, such as chimney sheep (which are naturally semi-permeable) or slightly under-inflated chimney balloons. Adding a ventilated chimney cap on top provides external airflow that prevents condensation from forming inside the flue.

Which chimney draught excluder is best for Lancashire homes?

For occasional fireplace users, a chimney balloon (£15 to £30) is the best all-round choice because it is completely removable and cheap to replace. For permanently unused chimneys in Lancashire’s damp climate, a chimney sheep (£20 to £40) is better because its wool construction allows some ventilation while blocking draughts, reducing the risk of condensation in the flue.