Here are some common ways to identify what kind of system you have: Conventional Forced Air systems often include gas or oil furnaces and central air conditioning. Air is typically blown through vents. Heat Pumps also blow air through vents. However, a heat pump system uses one outdoor unit to control both air conditioning and heating. It may also include a backup gas furnace. Radiant systems use hot water to heat the home. This may be done with baseboards, underfloor heating or radiators. If your Lyric thermostat is only controlling air conditioning in your home, select None (Cool Only).