This European Standard specifies the requirements and test methods for the safety and efficiency of domestic gas-fired air heaters with a fan to assist the transportation of combustion air and/or combustion products, hereafter referred to as appliances.This European Standard applies to Type B12, B12AS, B12BS, B13, B13AS, B13BS, B14, B14AS, B14BS, B22, B23, B42, B42AS, B42BS, B43, B43AS, B43BS, B44, B44AS, B44BS, B52, B53, C12, C13, C32, C33, C62 and C63 appliances with an input not exceeding 70 kW (net cv basis), intended primarily for use in single unit residential dwellings. Provision of the heated air may be by means of ducting.This standard does not app