You can select either geocentric or heliocentric coordinates from the drop-down Coordinate System list.
Most astrologers use the geocentric coordinate system. If you select the heliocentric coordinate system, then the chart will be calculated with heliocentric planetary positions on geocentric houses.
If you do not want to display geocentric houses on a heliocentric chart, then you could select "0 Deg Aries" as your house system, as this is a "neutral" house system which is independent of the chart’s location on earth.
