Higher efficiencies are achieved with geothermal (ground-source or water-source) heat pumps, which transfer heat between your house and the ground or a nearby water source. Although they cost more to install, geothermal heat pumps have low operating costs because they take advantage of relatively constant ground or water temperatures. Central Oregon Heating installs geothermal heat pumps in Bend, Redmond, Madras, Prineville, Sunriver and Sisters, Oregon.