How Does a Water Heater Work? | What Is a Water Heater?

How Does a Water Heater Work?

The water heater is one of the most important appliances in American households. A cold shower will remind you how much you should appreciate your water heater. Here we discuss an interesting question how does a water heater work? Before we get to that, let's answer an even more basic question.

What Is a Water Heater?

The short answer is, a water heater is a home appliance that heats the water supplied to the faucets, dishwasher, washing machine, etc. But let's clarify the question. When someone asks this, what they're probably asking is what is a storage water heater? There are storage tank water heaters and also tankless water heaters. Traditionally, homes are built with storage water heaters, but in recent history, there has been a push for tankless. Learn all about how tankless water heaters work

infographic depicting how a water heater works

How Does an Electric Water Heater Work?

  1. The water heater connects to the cold water supply, which fills the tank where it is heated.
  2. Electrical water heaters use the home's electricity to power the heating elements. Each tank usually has two heating elements (one at the top and one on bottom).
  3. The hottest water rises to the top of the water heater so that it's the first water out of the tank when someone turns on the shower.

How Does a Gas Water Heater Work?

  1. Just like with electric, a gas water heater connects to the cold water supply, which fills the tank where it is heated.
  2. The difference is that a gas-fueled water heater uses a pilot light and burner system to heat the water in its storage tank.
  3. Again, the hottest water rises to the top of the tank so that it's the first water out when someone turns on the shower.

Why Does Cold Water Reach My Tap First?

The reason for this is water sits idol in your pipes while all faucets and appliances are off. That water eventually arrives at room temperature. So when you turn on the hot water in your bathroom, the pipe has to be cleared of ambient-temperature water before the good stuff from the water heater hits you.

direct vent vs power vent

What Is a Direct Vent Water Heater?

For gas-fueled water heaters, a direct vent is a setup (a vertical pipe within a pipe) used to both take in air from outside and vent the air back to the outside. The advantage with a direct vent installation is it's cost-effective.

What Is a Power Vent Water Heater?

A power vent system uses a fan to push exhaust gas through horizontal venting. The advantage here is that vertical venting may not be an option for you.

What Is an Indirect Water Heater?

This is a system where the water heater does not use an element or burner within its tank to heat the water. It works by transferring heat from coils that run between the tank and a furnace or boiler.

For more general information, you can reference this Wiki: Water Heating article.

PlumbersStock: The Plumbing Experts

We hope that we've answered your question how do hot water heaters work? If you're in the market for a new water heater and have more questions, do not hesitate to contact us. Remember, we carry trusted brands like Bradford White, and here you will also find the best water heater parts in case you are in need of repairs.

Related resources:
Water Heater Buyer's Guide
Gas Hot Water Heater Venting Requirements
How to Replace a Water Heater (Tank)
Tankless vs. Tank Water Heater
How to Turn Off a Hot Water Heater

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