Gas leak is normally caused by rubber ring seal aging and wear & tear. Sealing element fixed in the end of gas line is commonly made of oil-resistant and gas-resistant nitrile rubber. Some of them are available in the stationary parts that are not able to move with other parts. That’s how they can be of longer life expectancy. Others are fixed to the sliding surface, which will move with other parts under the contact force, while contact extrusion will occur between them under external force.
The life expectancy will be shortened on account of friction and extrusion. With the increase of use time, deformation and wear caused by aging lead interference fit to cut down, which finally gives rise to gas leak. Additionally, the sealing performance will be weakened since the rubber material is exposed to the gas surrounding for a long time.
If there is a gas leak at the water heater, turn off the gas supply and open windows for ventilation. The gas water heater could not be used until the gas leak could be identified and handled.