Replacing a water heater requires a moderate skill level, according to The Family Handyman. The work is hard and requires the investment of several hours time. Replacing a gas water heater requires plumbing skills for water and gas, while the electric model requires working around water and electricity.
Hot water heaters have an average lifespan of five to 15 years. Water-heater leaks are the most common cause for replacement, as of 2015. Choosing a model of approximately the same size and that uses the same heat source makes the job easier, although homeowners who are considering changing to a different type of water heater find the time before a leak occurs the most economical for the upgrade.
Before beginning the replacement process, the installer shuts off the power or gas, and drains the tank. Tanks have a connector at the bottom for a garden hose that allows for draining them. If the water lines use soldered fittings, installing the new tank requires some soldering skills. Installing flexible copper supply lines at this time makes it easier to replace the unit when it fails the next time. Before turning on the electric water heater or lighting the pilot on a gas unit, the installer should fill the new tank with water by opening a nearby hot water tap and turning on the water supply to the tank.