Forced-air heating, cooling and ventilation appliances and components

Hot air furnace, air-to-air and water-to-air heat pump, air conditioner, wall unit, end unit, fan coil unit, rooftop unit, make-up air unit, fireplace and unit heater (except electric, see category 8 and 9), air exchanger, fan, exhaust fan, filter, duct, balancing damper, diffuser, fire damper, fitting, accessory, etc.

Hydronic heating, cooling and hot water production appliances and components

Hot water or steam boiler, combined hot water and space heating system, air-to-water and water-to-water heat pump, hydronic unit heater, circulator, heat exchanger, expansion tank, flow regulator, control valve, radiator, radiant floor system (except tube, see category 4), feeder, towel heater, valve, etc.

Plumbing fixtures and faucets

Toilet, urinal, bathtub, washbasin, sink, faucets, mixing valve, shower head and drain, shower base, roof drain, floor drain, sealing membrane, etc.

Pipes, backflow preventers, cisterns and accessories

Pipe and tubing for any fluid and gas conveying application, fitting, water temperature control device (when not integrated with a valve, otherwise see category 3), backflow preventer and vacuum breaker, check valve, water hammer arrestor, vacuum relief valve, air admittance valve, lift pump, sprinkler, separator (grease, oil, sediment, amalgam, etc.), gas and fuel storage tank, flange, support, glue, insulation, sealant, bolting, welding, brazing, etc.), gas and fuel storage tank, flange, support, glue, insulation, sealant, bolting, welding and brazing products, etc.

Tools, machinery, protective and other equipment

Tool, scanner, firewall, support, scaffolding, ladder, cleaning product, protective equipment, etc.

Software, controls and related component

Energy, lighting, communication and temperature controls, programmable controllers, estimating, design, and project management software, mobile applications, etc.

Interior and exterior lighting products

Lights, bulbs, etc.

Domestic electrical products

Wiring, conduit, connector, control panel and cabinet, transformer, baseboard, unit heater, wall-mounted unit heater, electric radiant floor, switch, towel warmer, fireplace, other electrical equipment, etc.

Commercial, institutional and industrial electrical products

Wiring, conduit, connector, control panel and cabinet, transformer, baseboard, unit heater, wall-mounted unit heater, electric radiant floor, switch, other electrical equipment, etc.