There's a huge difference between water heaters when it comes to price, technology, performance, and long term cost. Matt Risinger discusses the differences between 3 water heaters. One heater is $500 with a 6-year warranty, another $1100 for a lifetime warranty, and the last is $1500 for a 10-year warranty. The energy guide is this first thing to look into, as it will really set each apart from another, telling you how many heated gallons of water it can produce in the first hour. What about the annual energy cost? They can range from $110 a year to $1000s. Some of these water heaters use hot air from the air in your home to use as energy, while others use hot air which can affect your energy cost in terms of heating and cooling your home. After first year of energy and the cost of the product itself, these heaters definitely vary in terms of how much it'll cost you over time. If you're replacing an older unit you may want to take a look at this video to see some of the pros and cons.