Best Twin Wall Flue When buying twin wall flue there are various things to consider when looking for the best: Is the flue HETAS approved? HETAS is the governing body ensuring the standards of flue and chimney manufactured products and tradesmen meet the latest regulatory standards in the UK. All of our flue supplies are HETAS approved and tried and tested since our business started in 2001. Is the twin wall flue easy to install and go together easily? A simple push fit system with clip on locking bands like ours is the easiest to fit on the market and one piece fits to another in a matter of seconds. What is the distance to combustible materials of the twin wall insulated flue? A highly rated twin wall flue with condensed insulation material between the inner and outer stainless steel skin of flue ensures the flue can be used as close as possible to anything combustible. Flue Direct twin wall flue is the best on the market at only 50mm to combustible materials! Consider the aesthetics of the flue - our twin wall flue has flush mounted locking bands for a seamless and sleek finished look and design. Available in plain stainless steel finish or black powder costed you have the choice of each or to combine the two, plus our Black twin wall flue is a close match to the colour and finish of your stove / wood burner. Warranty - Our TW Pro twin wall flue comes with an unbeatable 25 year Warranty!