This means that you'll be able to search for NAICS codes directly (if that's your jam). We'll do the math; let's make better data on public procurement together.
Oil Burners; Stokers; Gas Burners.
Possible NAICS Codes
333414 – Heating Equipment (except Warm Air Furnaces) Manufacturing
238220 – Plumbing, Heating, and Air-Conditioning Contractors
339991 – Gasket, Packing, and Sealing Device Manufacturing
336411 – Aircraft Manufacturing
333415 – Air-Conditioning and Warm Air Heating Equipment and Commercial and Industrial Refrigeration Equipment Manufacturing
332410 – Power Boiler and Heat Exchanger Manufacturing
457210 – Fuel Dealers
333914 – Measuring, Dispensing, and Other Pumping Equipment Manufacturing
333618 – Other Engine Equipment Manufacturing
444140 – Hardware Retailers