Electric water heaters do not need to be vented as electric water heaters do no produce any carbon monoxide like gas or propane water heaters do.
However the pressure relief valve should exit to the outside to allow any possible water from the water heater pressure relief valve to exit and not get into the house.
The lifespan of an electric hot water heater is between 10 to 15 years although some electric water heaters can last 20 years.
If maintained properly the electric water heater should last at least 10 years to 15 years.
If your electric water heater is older than 15 years or is getting close to 15 years old then you should look into replacing it soon as the water heater tank could eventually burst open unexpectedly and cause a major flood in the house.
Even if the electric hot water heater tank looks good it can be bad on the inside.
So if your electric water heater is older than 10 years or older than 15 years and is still working it still is a good idea to replace it to prevent other costly damage to the home.
Signs that your electric water heater is going bad include.
Water Is Discolored or Gritty. Inside your hot water heater there is a component called an anode rod.
Hot Water Smells Off.
Tank Is Leaking Water.
Heating Process Makes Strange Sounds.
Hot Water Runs Out Too Quickly.
Water Never Gets Hot Enough.
There's No Hot Water At All.
While today's water heaters are better designed than older models, they still require regular maintenance in order to prolong their lives.
With regular inspection, draining, and flushing, you can expect a gas water heater to last anywhere from 8-12 years and an electric water heater to last anywhere from 10-15 years.
Tankless water heaters typically have a lifespan of 20 years or more.
Traditional water heaters with standing water tanks can last around 10 to 15 years before you notice signs of age.
Parts that most often go bad on electric water heaters include.
Heating Elements. Often, problems with electric water heaters come from faulty heating elements.
Thermostat. If the heating elements are operating correctly, another cause may be a thermostat issue.
Anode Rod.
Dip Tube.
Pressure Relief Valve.