Gas Infrared Heaters HL-3 Series Two Stage 65,000 - 200,000 BTU Troubleshooting Manuals* DX-3 Series Single Stage 50,000 - 200,000 BTU Select... HL HL-2 DX HLV SV DTHS XTS-3 Series Economy 50,000 - 200,000 BTU DES3 / DET3 Lowest Cost 50,000 - 200,000 BTU LS / LD Low Input 25,000 - 50,000 BTU Tube He...