This document specifies, for the purpose of type examination, the requirements and test methods for construction, safety, marking and rational use of energy of 2nd and 3rd family gas-fired domestic flueless space heating appliances having a nominal input not exceeding 6 kW (based on net calorific value).It covers the following Type AAS fixed flueless heaters:NOTE These are type A appliances fitted with an atmosphere sensing device, with or without a fan.a) heaters with or without a catalytic converter;b) Category 1 appliances burning gases of the second family; c) Category 2 appliances burning gases of the second and third families.It does not cover i. Mobi