There are a few reasons for why you might want to put a bowl of water in front of your heater. One reason is that the water can help humidify the air in your home, which can be beneficial during dry winter months. Additionally, the evaporating water can help circulate warm air from the heater around the room. Finally, having a bowl of water in front of your heater can also help prevent dust and other particles from being blown around by the heat.