Genuine Daikin 1281578 Indoor Float Switch is the switch that detects when condensate water rises too high in the indoor unit's drain pan, so the unit can stop before it overflows. When it fails, the unit may shut down with a water-related warning, or fail to stop and let the pan overflow. A genuine switch trips at the level your Daikin expects, keeping that protection reliable — where a non-genuine part can trip falsely or miss a real rise.