ENGLISH RAIS - manual for Q-BIC & Q-BIC insert9If it is found that there is excessive draught in the chimney then either an adjustable fluedamper or alternatively a draught stabiliser should be fitted. The adjustable flue dampershould not close off the flue entirely but should in its closed position leave a minimumcontinuous opening free area of at least 20 % of the total cross sectional area of the flue orfluepipe.Adequate provision e.g. easily accessible soot door or doors must be provided for sweepingthe chimney and connecting fluepipe.You should also familiarise yourself with the draught conditions for chimneys with 2 flues.The flue outlet spigot is 150 mm in diameter.For strong draughts, the chimney or flue should be fitted with a draught stabiliser. In whichcase, it is important to ensure that there is a free flow-through area of minimum 20 cm² whenthe regulating gate is shut. Otherwise, the fuel energy may not be used optimally. If, at anytime, you are unsure about the condition of the chimney, you should contact a chimneysweep.Remember that access to the access door should be kept clear.