MTFD was dispatched to the Hampton Inn for an Automatic Alarm at 20:38. Command sent the crew from Engine 57 to the 3rd floor vending area and found a leaking hot water heater above the smoke detector. While on scene a guest stated they smelled gas near the pool area.  The crew from Engine 75 checked the pool area with a gas meter and came back with negative readings. MTFD cleared the scene within an hour.