An in-depth study of placing propane and natural gas utilization equipment into service while controlling gas/air mixtures for proper combustion. Gas equipment installations including: clearance to combustibles; combustion, dilution and ventilation air requirements to determine if a space is confined or unconfined. Gas equipment venting, including venting categories, vent materials, vent sizing and clearances. Troubleshooting electrical circuits and control devices while measuring electrical quantities using an electrical meter. Identifying operating characteristics and components of common sensing devices will be covered. Gas pressure measurements including supply and appliance burner pressure detection will be discussed. Ignition safety systems including the 100 percent pilot safety shut-off and other electronic safety shut-off devices will be studied. Flue gas analysis and carbon monoxide detection will be included. National Fuel Gas Code as it relates to the above topics is also emphasized. Prerequisites: HVAC134M, HVAC135M.