Circle G Service Co in Columbia, MO are radiant heat specialists, plumbers and heating contractors offering service, installation and repair of air conditioning systems and heating systems. Circle G Service Co also offers innovative hydronic heating, sealed combustion boilers, geothermal systems, video camera sewer inspection and jetting, back hoe work, and work on new construction sites.. Air Conditioning Contractors; Heating Contractors; Plumbing Contractors; Back Hoe Work; Heating; Hot Water Heat; Innovative Hydronic Heating Systems; Low NOX - Under 20PPM; New Construction; No Pilot Light. Hot Surface Ignition; Plumbing; Radiant Heat Specialists; Repair; Sealed Combustion Boilers; Unilo; Video Camera Sewer Inspection and Jetting Available; Geothermal Systems