When it comes to your hot water dispenser, the difference between a drip and a leak is the key to knowing if a flood is in your future. Here's how to tell. Because water's volume increases with heat, a few drips from a hot water dispenser or faucet is simply a release of the pressure in the water tank under the sink. However, if the leak is continuous, the shut-off valve may need to be repaired. Consult a professional if your dispenser has had one drip too many.