11 Heating apparatus, namely, sauna heaters, steam generating apparatus, namely, steam generators, drying apparatus, namely, electric clothes drying machines for household purposes, ventilating apparatus, namely, ventilation exhaust fans; gas burners for industrial purposes; mechanical appliances for the production of heat, namely, central heating radiators; non-automatic liquid-purifying separators for steam heating systems; attachments in the nature of brackets for gas burners; friction lighters for igniting gas; lighters, namely, spark igniters for gas appliances; acetylene burners; furnace fittings, namely, air filters for furnaces; burners, namely, gas burners; steam generators; steam accumulators; air heaters, namely, hot air space heating apparatus for industrial purposes; air filters for domestic use; gas burners; gas boilers; gas condensers, other than machine parts; hot air apparatus, namely, hot air space heating apparatus for industrial purposes; heating apparatus for solid, liquid or gaseous fuels; heating boilers; water-tube heating boilers; feeders for boilers, namely, water control valves for heating boilers; electric radiators; fan heaters, namely, electric heating fans; heaters, namely, heating units for industrial purposes; heating radiators; pipes for heating boilers; electric air dryers; air conditioning ventilation apparatus; combustion furnaces, namely, blast furnaces; oil burners for commercial use; heat pumps; electric radiators; flues for chimneys; smoke dampers for heaters, namely, control devices used in heating installations to regulate the flow of air; control and safety accessories for gas appliances, namely, flashback arrestors and reverse flow check valves; coils as parts of heating installations; heat accumulators; evaporators for air conditioners; heat recovery ventilators; heat exchangers not being parts of machines