Downdraft is a common issue that affects solid fuel applicances such as woodburning stoves. It usually only occurs when the stove is first lit.

Smoke comes out of the stove in puffs or there is a lot of smoke inside the stove. It can also be overly difficult to light the fire and it can be slow for the fire to fully take.

The most common cause for this is a downdraft in the flue. This is often caused either by atmospheric conditions around the end of the flue or by poor installation. If it is occasional, then the problem is likely to be caused by atmospheric conditions (especially strong winds from an unusual direction for instance). If this is happening frequently, then you are likely to have a problem with the way the flue is fitted.

Changes around the flue (trees are a common culprit as are recent builing work either to your home or by your neighbours) can cause the flue to become sheltered, this will typically result in a downdraft in the flue. Damage done to the cowl or debris caught in the end of the flue might also be the cause of the problem. If the problem has persisted since installation, then it is likely that the flue doesn't reach high enough.

The first thing to do is to try warming the flue. Heating the flue itself can reverse the downdraft (through the simple principle of hot air rising.

Check that the end of the flue is clear and that the cowl is in good repair. The problem can be solved by extending the chimney or fitting an anti-down draft cowl.