Does the gas water heater in my laundry room require a dedicated vent?
He's talking about a combustion air intake. Fuel burning appliances are not allowed to draw combustion air from habitable rooms. So it's possible that a combustion air intake may be required. 

Check with your local building department, to determine if one is required in your situation. 

If the dryer vent and the heater exhaust through the same duct, that's definitely a problem.   Though hopefully that's not what you're talking about.