It all depends on the type of water heater you're using. Here are some common heat up times for different water heaters, assuming the appliances are new and properly sized for the home: Electric storage tank water heater: 60–80 minutes. Propane storage tank water heater: 30–40 minutes.

For an electric water heater, you'll need to locate the circuit breaker that controls the heater and turn it on. If the breaker isn't labeled, look for a double-pole breaker that has the same amp rating as the heater. Simply switch on the breaker to turn on the electric water heater.