When you find that there is a gas emergency in your house, and you can actually smell it, then calling the emergency gas engineer at the earliest should be the only solution. Of course, you might not be able to prevent the leak, but it is important for you to take precautions in order to prevent it from becoming a catastrophic event. Gas is inflammable, and therefore it can lead to a very big problem if you have your family members living with you in your house.
With the services of a 24 hour gas engineer, you will be able to prevent any kind of problems spiraling out of control. It would also do you a whole lot of good turn off the gas supply or even the emergency control. If you feel that there are problems related to the boiler, then shutting down the boiler would be your best bet. If these things are done properly, then you would be able to minimize the risk significantly. Then, you can wait for the gas engineer to arrive and take stock of the situation.
When you have a gas engineer on the scene, then the person will be able to conduct all the gas checks, and ensure that there are no further leakages. Then, the engineer would conduct a thorough search of the entire place to find out if there are any other problems within the house of the establishment itself. After that, the diagnosis will be done about the leakage and it shall be plugged immediately. These are is this some of the steps which a gas engineer would undertake at the scene. Amongst all the other things, you also have to realize that a gas engineer that has proper credentials will be able to seek and find that the problem very early.