1) There are a wide variety of residential water heaters that range in capacity from fifteen to one hundred gallons. They can be expected to last at least as long as their warranty, or from five to eight years, but they will generally last longer. However, few of them last longer than fifteen or twenty years and many eventually leak. So it is always wise to have them installed over a drain pan plumbed to the exterior. Also, it is prudent to flush them annually to remove minerals that include the calcium chloride bi-product of many water softening systems. The water temperature should be set at a minimum of 110 degrees fahrenheit to kill microbes and a maximum of 140 degrees to prevent scalding. Also, water heaters can be dangerous if they are not seismically secured and equipped with either a pressure/temperature relief valve and discharge pipe plumbed to the exterior, or a Watts 210 gas shut-off valve.
1) There are rust particulates within the combustion chamber, and smothering (or covering) the burner, which should be removed.
2) There is rust on the outside of the water heater tank. Typically rust can occur due to condensation, or in the presence of a leak. While there was no active leak at the time of the inspection, one could have occurred in the past, and could again.
3) There is evidence of hot combustion gasses escaping from the combustion chamber. This is typically known as ' flame roll out' and is an obviously an unsafe condition. Due to these issues, we recommend evaluation and/or service by a licensed plumber