ELECTROCHEMICAL FUEL CELLS, SAFETY EQUIPMENT FOR HEATING DEVICES AND HEATING SYSTEMS, NAMELY, THERMOSTATS AND TEMPERATURE CONTROLLERS, HEAT-DISTRIBUTION REGULATORS AND CONTROLLERS, FLAME AND COMBUSTION MONITORS, EMISSION CONTROLLERS, BURNER CONTROLLERS, HYDRONIC CONTROLLERS, COMFORT CONTROLLERS, WATER-HEATER CONTROLLERS, REMOTE AND ON-SITE CONTROLLERS, SERVICE NEED INDICATORS, POWER REGULATORS AND CIRCULATOR AND PUMP CONTROLLERS FOR CENTRAL AND LOCAL SPACE HEATERS, HEAT EXCHANGERS, CONVECTORS...