There are a number of alarming factors that determine the existing heater’s life has come to an end and it would no longer serve you. We will mention 2 ways of knowing whether your gas heater has exhausted and if it is the time to replace it. The first being the leakage of any kind, look out for water build-up in and around your heater. The next is the comparison or the difference you notice. If you notice the water is no longer getting heated the way it used to in the past, it is time you need to think about replacing your gas water heater.