Carefully inspect the tubing to the grill for any damage.
Maybe it got hit by something causing it to become pinched.
If the tubing is damagen in any way, you must replace it. It's no longer safe and may cause adangerous leak.
Also check for any kind of debrit that may have found it's way into that pipe.
A blast of compressed air may be enough to clear the obstruction.
With hope, February 2015
