If you smell gas or hear a hissing sound coming from your gas grill, you will need to find and repair the leak before igniting the burners. Fortunately there are few connections you can check when pinpointing a gas grill leak. The most common area for a leak is the regulator hose connection. The regulator hose connects the propane tank to the gas line, and it regulates the amount of fuel pressure to the burners. Fixing a gas leak requires finding the exact source of the leak and either tightening or replacing parts.
Turn the gas valve on the top of the propane tank clockwise until it stops to shut off the gas. Turn off all the burners on the grill. Allow the grill to cool completely before attempting to fix the gas leak.
Mix 4 tablespoons of liquid dish soap with 1 cup of water. Turn the propane tank valve counterclockwise until it stops. Use a small paint brush to apply the soapy mixture where the regulator hose connects to the tank and the burner valve under the grill.
Brush the soapy mixture over each connection on the gas line behind the grill burner knobs. Gas leaks are visible when the soapy mixture begins to bubble. Once you identify the gas leak, shut off the propane tank.
Turn the regulator hose connection at the tank counterclockwise with your hand. Turn the regulator hose connection under the grill at the gas line counterclockwise with a wrench. Remove the regulator hose and inspect it for cracks. Inspect the threads for wear if you found leaks at the connection.
Replace the regulator hose with a new one if there is damage to the hose or threads at the connection nut. Clean the threads on the gas valve fitting under the grill with a stiff brush if leaks were present at the connection.
Thread the end of the regulator hose opposite the regulator onto the gas valve fitting under the grill until it is hand tight. Turn the connection another half turn with a wrench. Screw the regulator end of the hose onto the propane tank until it is hand tight.
Tighten the screws securing the grill control connections to the gas line that runs behind the control knobs, using a flat-head screwdriver.