Heating installations, [ namely, ] hot water heaters, [ electric radiators for heating buildings, electrical heating apparatus, namely, electric heating fans, electrical boilers, heat pumps, ] heat [ and steam ] accumulators, heat exchanger, [ solar collectors for heating installations, ] hot water space heating apparatus, [ and ] heating apparatus, [ namely, heat pumps for domestic hot water circulators, heat pumps for secondary circulators for mechanical building and industrial services, solarthermic heat pumps and structural parts therefor; ] hot water heaters, namely, central hot water heaters, secondary hot water heaters, [ and service hot water heaters, ] open condensation hot water heaters, hot water apparatus, namely, hot water tanks, [ electric heating boilers, namely, electrical boilers, furnace boilers, industrial boilers, ] heating elements, [ namely, electrical heating cables; heat pumps, ] heat accumulators, pressure accumulators [ as part of heating and water conduit installations, namely, heat accumulators, steam accumulators ]