One problem that we see regularly and causes the most worry with regard to potential danger is that gas fires are often connected to flues that haven’t been swept for a long time. Sometimes we are called to properties because of the amount of debris that has fallen down the chimney has resulted in the fire stopping working or being condemned by a gas engineer.
It seems to be a common misconception that gas fires do not produce any smoke or soot and therefore the chimney never needs cleaning.
However, gas fires dry out the flue and this results in the lining slowly degrading and producing a substantial amount of cement dust.
We would suggest that if you have a gas fire you should have it swept once a year.