11 Heating apparatus and heating systems; air-conditioning, refrigeration and ventilating apparatus and installations; water heaters; combined apparatus and installations for heating, refrigerating, air-conditioning, hot water, ventilation and aeration; apparatus and installations for steam generating, water supply and sanitary purposes; heating boilers; heaters for instant hot water; air heaters; burners, in particular for fossil fuels and renewable fuels; fittings for heating apparatus and burners, included in this class; block-type thermal power stations; heat pumps, namely air, geothermal heat, electric, gas, solar and water heat pumps; heat accumulators for use with water heaters and storage water heaters; heat exchangers; solar heating installations and individual components; solar collectors; mounts, roof mounts and assembly systems for solar heating installations and individual solar components; panel radiators; radiators; wall, ceiling and floor radiators and systems consisting thereof; parts and fittings for the aforementioned heating and hot water systems, including heat pumps, gas fittings, thermostatic valves, and air and gas exhaust pipes; safety accessories for water or gas apparatus and pipes