The answer to 'how long does water heater last' is that the average lifespan of a water heater is 8 to 12 years. However, this can vary depending on the type of water heater, the quality of the unit, and how well it is maintained. Proper maintenance, such as flushing the tank and checking the anode rod, can help extend the life of a water heater.
Water heaters that are well-cared for and located in a mild climate tend to last on the longer end of the spectrum, while those in harsher environments or with less maintenance may need replacement sooner. It's a good idea to monitor your water heater's performance and be prepared to replace it when it starts showing signs of age or wear.