What grade of liner do you require?

There are two grades of steel for your lining system. The quality of stainless steel used for the inner and outer layers of the liner affect its lifespan and recommended usage. 316 which has a ten year guarantee is only suitable for use with wood and very occasional smokeless fuels. 904 has a 20 year guarantee and is suitable for a mixture of wood and smokeless fuels and is recommended for people planning on heavy use of  their stove, especially with coal.