I installed a new electric water heater and by mistake, I connected the incoming cold water line to the hot side on the tank and the hot water out line to the cold water side of the tank. I then filled the tank and turned on the power. It was not until a couple hours later when I went to check for the hot water did I discover my mistake.

Have I damaged this new electric water heater?

Have I damaged this new electric water heater?

No! Simply reverse back hot and cold water pipes, and you'll be just fine. Good luck, Tom

Agreed! No Damage as long as you filled the tank before you turned power on to the water heater....good news, for sure!

As you suspect, however, you'll need to swap the pipes back because the cold water inlet to the water heater has a dip tubethat directs cold water to the bottom of the tank and that is important in hot water delivery and recovery...;)

Mark