Recently I discussed the importance of cleaning your Venturi Tubes. Equally important to the maintenance of your gas grill and the not burning down of your house is checking for gas leaks. These two culprits account for the vast majority of fires associated with gas grill. Propane is heavier than the air around us. Meaning that they will fall down from your grill. If you have an enclosed cart or an enclosed space that gas can collect in large amounts, particularly on a windless day. Natural Gas is lighter than air and can fill the hood of a gas grill. So checking your grill for leaks is the most important common gas grill problem you will encounter. Propane and Natural Gas have distinct odors (thanks to an additive to them) so if you have substantial leaks you might be able to smell them. However, this isn't sufficient a test for finding ALL potentially explosive leaks.
To check your grill for gas leaks you need a small basting brush and a bowl of very soapy water. To check for gas leaks you need gas, so make sure your fuel tank is full and that the tank valve is in the on position. This will pressurize the fuel lines from the tank to the control valves. Do not light the grill. Do not smoke. Do not have any open flames anywhere nearby. Now brush your soapy water over all hoses and connections. Apply slowly and watch for bubbles to form. Any place you have bubbles forming (there will be bubbles from the application already) you have a leak.
Leaks can be caused by loose connections or by cracked or broken hoses. Once you have identified any potential leaks turn off the gas and disconnect the fuel line. Loose connections can be tightened but cracked, broken or worn parts will need to be replaced.