A gas grill regulator-and-hose assembly controls the flow of propane from the tank to the burners inside your grill. The regulator is a safety mechanism designed to shut down automatically if there is a break in the gas line. Over time, the regulator and hose, which typically are permanently attached to each other, can become worn and require a replacement, which is available at hardware stores.
Put work gloves to protect your hands from sharp metal edges on the grill. Shut off the gas at the propane tank, twisting the valve knob clockwise by hand until tight.
Unscrew the black coupler attached to the valve stem on the side of your propane tank, turning counterclockwise by hand. Unless you plan to replace the entire hose-and-regulator assembly, do not use pliers or other tools to loosen the coupler, which is made of plastic that can crack.
Spray short bursts of silicon lubricant spray on the brass couplers on the other end of the hose-and-regulator assembly where the couplers connect to the valves behind the burner-control knobs. Wait 10 minutes for the lubricant to loosen the couplers.
Twist the rotating ring on each coupler counterclockwise with pliers to disconnect the regulator hose from the grill. Depending on your model, you may have a two-hose regulator connected to two burners or a single hose attached to the grill.