Dormer Bungalow Flexible Flue Liner: 316L Grade Flue Liner is warranted for 10 years (conditions apply). Suitable for Wood, Low Sulpher Coal, Oil, Gas Application: A double skinned flexible flue liner suitable for relining within a masonry chimney. Flue liner is suitable for use with burning gas, oil, coal, coke, cured dry logs, dry peat. If the appliance is mainly going to be used to burn wood, and the appliance is not DEFRA approved you should increase the diameter of the Flue Liner to 150mm (providing this will fit in the masonry chimney), as recommended by Building Regulations. Construction: The flue liner has a smooth inner liner made from 316L grade stainless steel and is 0.12mm thick. The flue liner has a convoluted outer skin made from 316L stainless steel and is 0.12mm thick. Approval: Flue Liner is approved and listed by HETAS Pre - Installation: · Make sure the liner will go down the chimney (this can be done by pulling down a small section of the diameter liner you will be using) · Sweep your chimney. · Check you pot is in good condition, if you are NOT using a suspended cowl then remove the pot from the stack. Installation: · Flue Liner should always be fitted from the top. · Make sure the arrows are pointing upwards (gas flow). Maintenance: · It is recommended that chimneys serving solid fuel appliances be swept and maintained as frequently as necessary but at least once a year.