Twin Wall Flue

Roccheggiani DP25 Black Twin Wall Flue Systems

Colt Cowls offer the very high quality sought after Italian twin wall flue system Roccheggiani DP25.

Regarded as one of the highest quality twin wall flue systems in Europe, Colt Cowls offer both the more popular black powder coated stainless steel system and the natural finish stainless steel.

Manufactured by Roccheggiani in Italy the DP25 double wall series is the leading product in Roccheggiani's range of flue systems. It can be used for a wide variety of purposes whether installing a traditional stove or modern high efficiency condensing appliance, the DP25 twin wall flue offers the ideal solution.

DP25 is a double wall system that can be installed both inside and outside thanks to an efficient thermal insulation system made of high density rock wool, which guarantees the optimal performance in all weather conditions.

The new flues are easy to install, weatherproof fully sealed components made to give uncompromisingly the best possible performance for both installation and use. The range has been tested and approved to EN 1856-1 with the following designation T600 N1V2L50500 G50

The system is available in 5/6'' matt black and stainless steel finishes which come with a comprehensive warranty.

Roccheggiani twin wall flue systems are available with FREE next day delivery (order value ove £750 Ex VAT - below that carriage rates apply)

Either order right here online, or through the trade login  or simply call 01243 781559 to place your order over the phone.


Previously, Colt Cowls sold Holetherm Twin Wall which is still available, but stocks are being reduced so not all components are still in stock. Information on Holetherm twin wall flues is as follows:


Stainless steel twin wall insulated flue systems.

Holetherm is a high quality all fuel chimney flue system manufactured in stainless steel (316 inner and 304 outer wall) to the highest quality standards. Insulation between the walls is provided by a high temperature resistant fibre mat.


The products are manufactured in an ISO 9001 certified factory and the system is CE marked and certified for use in all fuel systems when installed according to the fixing recommendations supplied with each item. Continuous laser welding of all the key seams ensures an exceptionally high quality finish and reliability in construction and use.
Tested and certified to BSEN-1856-1:2009 and HETAS listed


On going and substantial investment by the company in automated processing has resulted in highly competitive production costing and resultant value pricing for the user.

Construction and dimensions

The system is assembled from a range of standard parts illustrated in the following pages. The push fit and locking band system has been tried and tested over more than 25 years and has been installed in over 100,000 homes in Europe. Available in 2 standard internal diameters 125 and 150mm, and 7 made to order diameters 175, 200, 250, 300, 350, 400 and 450mm.
Installation instructions are supplied with each component.


All parts are available with free next day delivery (popular sizes only) from our warehouse.