We have a forced air furnace - run on gas. This morning, I discovered my precious 3 year old pouring a glass of water down the vent on the bathroom floor. Of course, I shut the vent immediately and poked my head around the furnace room. But found no visible signs of water anywhere.
Should I be looking elsewhere or doing something else?

Usually water will flow down to the furnace and disipate. It is possible the water is just laying in a low spot in the duct work. The heat of the furnace will cause the water to evaporate over a short time. I cannot see a big problem over this.