Water Heater Guide: Learn About The Parts Of Your Water Heater (And More!)

Nobody really pays too much attention to their water heater until it stops working and we are left without hot water for our showers, dishes, and more.

Water Heater Guide: Learn About The Parts Of Your Water Heater (And More!)

This is an unpleasant situation to be in, especially if you have a busy lifestyle!

So, it is important to keep our water heaters in prime working conditions to ensure they do not break down – or we can easily fix them when they do!

To make this possible, we need to understand our water heaters.

More specifically, we need to learn about the different parts of a water heater1  By doing so, we will know when to replace them, when to repair them, or when we are being overcharged for any necessary work on them. 

In this article, we will discuss all of the above and more, so make sure you stick around! 

What Is A Hot Water Heater? 

First things first, let’s make sure the definition of a water heater is clear.

A water heater is a type of tank that heats, stores, and provides hot water wherever it is necessary, such as in the shower or the kitchen faucet. 

Water heater tanks are typically lined with steel, and this is accompanied by either cement, porcelain, or glass.

The outside is then wrapped with an enamel metal jacket and insulation. 

What Are The Main Parts Of A Water Heater? 

All water heaters, no matter if they are powered by oil, electric, or gas, have the following parts in common: 

  • Flue 
  • Cold water valve 
  • Draft diverter 
  • Electrical supply 
  • Temperature-pressure relief valve 
  • Overflow pipe 
  • Hot water outlet 
  • Anti Corrosion anode rods 
  • Dip tube 
  • Upper element 
  • Insulation 
  • Lower element 
  • Drain valve 
  • On and off pilot temperature control 
  • Burner 
  • Upper thermostat 
  • Lower thermostat 
  • Thermocouple 
  • Shutoff valve 
  • Air shutter 
  • Gas supply 

Water Heater Components: Anti-Corrosion Anode Rods

Water heater tanks have 1-2 aluminum or magnesium anode rods that protect any exposed steel from becoming corroded.

They are sometimes called sacrificial anode rods or anti-corrosion rods. 

If your water heater has a 10+ year guarantee then it will typically have two rods for extra security. 

If you have soft water in your area/home, then it is best to use magnesium anode rods.

However, aluminum anode rods are best if your area/home has hard water (Check out How To Get Rid Of Toilet Ring? Fast Results). 

Sometimes, hot water tanks will become contaminated with desulfovibrio bacteria.

This type of bacteria will thrive in hot water tanks thanks to the magnesium anode rods.

Consequently, the hot water will smell like rotting eggs.

So, if you notice this smell in your own hot water tank, it is best to get the water tested to make sure it is not contaminated. 

If your water is contaminated with bacteria, then the best thing to do is to chlorinate your tank and then change the magnesium anode rods to aliminum anode rods. 

Water Heater Components: Cold Water Shut-Off Valve 

The main line water conditioning/softening system has a pipe that supplies water to the hot water heater.

You should be able to find a shut off valve for the cold water supply on the water heater “supply” side.

Here, you will be able to easily turn the water on and off if you ever need to replace or repair any part of your water heater. 

Water Heater Components: Dip Tube, Inlet Pipe, Outlet Pipe

The inlet pipe is on top of the water tank and will send cold water to the bottom via the dip tube.

This way, the cold water will not cool down the hot water in the tank.

The hot water then leaves the water tank through the outlet pipe, which is situated at the top of the tank. 

Sometimes, you will see that the outlet and inlet pipes are reversed because this is more convenient.

If this is the case, then the dip tube will be moved to the outlet pipe. If it has not been, then this may cause problems. 

Water Heater Components: Temperature-Pressure Relief Valve

Relief valves are there to protect the water heaters.

They allow the water to escape the heater if the pressure of temperature becomes too high.

This safety measure is in place so the tank does not blow up. 

You should be able to find the temperature-pressure relief valve at the top or on the side of the tank.

If you see it on the top of the tanks, it indicates that you have an older water heater model, and you may want to consider replacing it.

This is because the practice of placing the temperature-pressure relief valve on top of the water heater is no longer considered safe. 

You should be able to see a discharge tube or metal extension tube down the side of the tank, around 6 inches from the floor.

This tube will make sure that any steam or hot water does not spray onto anyone standing close by.

The bottom of this extension will not have a turn-off valve and it will not be threaded at the bottom.

This is so nobody can plug or cap the extension. 

If you notice that the relief valve is leaking, you should not attempt to repair it. It will need to be replaced instead. 

Water Heater Components: The Thermostat And Operating Controls 

Generally, hot water heaters have 140 degrees of output water, but you will be able to change these settings via the thermostat.

Water Heater Guide: Learn About The Parts Of Your Water Heater (And More!)

If you want a more energy efficient and safe water temperature. Then anything between 115-120 degrees is typically recommended. 

You can use a screwdriver to adjust the temperature for electric water heaters. 

Meanwhile, you will find a knob or dial thermostat near the control unit of gas water heaters.

Water Heater Components: Drain Valve 

There should be a drain valve at the base of every water heater tank.

You should attempt to drain out a few gallons of water multiple times a year to make sure sediment and sludge does not build up in your water heater. 

The Varying Sizes Of Water Heaters

Did you know that water heaters can vary in size? The size of a water heater is typically measured in gallons. Here are the most common sizes: 

  • 40 gallons 
  • 50 gallons 
  • 66 gallons 
  • 75 gallons 
  • 80 gallons 
  • 120 gallons 

But you can find some that are even bigger or even smaller than this! 

What Water Heater Is Best For You?

So, now that you know there are many types of water heaters, you need to work out which water heater is best for you. 

This depends entirely on the size of your home and family.

For example, if you are a family of four, then some standards will recommend a water heater tank of 80 gallons.

This is provided you have utilities like a dishwasher and a clothes washer.

But, you will probably find that most homes have a 40-50 gallon electric water heater or a 40-gallon oil or gas heater. 

How Long Before Your Hot Water Heater Recovers?

It is very common to use all of the hot water from your tank.

When this happens to you, you may find yourself wondering how long it will be before your hot water returns and you can wash your clothes and take a nice, warm shower. 

So, here are some examples of how long it will typically take for your hot water returns! 

  • Gas water heaters: 1 hour recovery time 
  • Large, water heaters with a specific high recovery rate: 15-30 minutes recovery time 
  • Electric water hearts: 2 hours recovery time 
  • Oil water heaters: 1 hour recovery time per 120 gallons of water 

Where Can You Find A Hot Water Heater?

You can find a hot water heater in various places. Let’s check them out! 


If your hot water heater tank is outside, then you should find it situated 3 inches above the grade and on top of a concrete pad.

Living Area

If your hot water heater is situated inside your home, then you should find it situated on a wooden floor with a drip pan underneath it. 


If your hot water heater is inside a garage, it will typically be an oil or gas heater and it should be around 18 inches adobe the ground.

This will help to stop the accidental ignition of gasoline vapors. 


This is one of the most common locations of water heaters.

It is typically the safest place to keep them and will not ruin your home aesthetic.

On top of this, there is a ;low chance of there being water damage to any of your possessions if there is ever a leak in the water heater. 

Your water heater will most likely meet regulations if it is situated on an outside wall, which allows room for a flue. 

It is important to note that water heaters powered by oil or gas should not be installed in bathrooms, bedrooms, or closets.

This is because in order to work properly, these water heaters need continuous and satisfactory air supply.

Water Heater Guide: Learn About The Parts Of Your Water Heater (And More!)

How Do Water Heaters Vent?

Water heaters must be able to vent safely or else you and those in your household are at risk of carbon monoxide poisoning.

This is why water heaters powered by fossil fuels need to vent outdoors.

This will typically happen via a chimney or direct;y through an outside wall. 

So, oil and gas water heaters need a flue pipe that will go from the tank right to the chimney, which requires a slope of around a quarter inch going upwards per 1 foot of pipe.

If your flue pipe is single-walled, then it needs to be installed around 6 inches away from anything that can combust. 

A double-walled flue needs to be able to vent 1 inch above the roof minimum, and 2 inches minimum for a single-walled flue. Depending on the roof’s slope, this could be higher. 

Additionally, draft hoods prevent carbon monoxide from re-entering the home, so it should be installed on top of the tank. 

What Is The Average Life Of A Water Heater?

The average life of a water heater depends on various factors.

Before you get a new water heater, it is a good idea to check how old your current one is.

You should be able to answer the following questions before you consider getting a new water heater:

  1. How long should my water heater last?
  2. What is the manufacture date? 
  3. What factors go into lengthening or shortening the life of a water heater?

Once you can answer these, you will be able to determine whether or not you need to replace your old water heater. 

Typically, there are six things that go into determining if your water heater needs replacing. They are: 

  • Age 
  • Water
  • Type
  • Maintenance 
  • Location 
  • Quality 

Let’s check each of these out in closer detail!

Water Heater: Age 

Typically, water heaters will have anything between eight to twenty years of life, so it is good to know how old your unit actually is.

If you do not have the receipt and do not know when it is installed, you will need to decode the serial number on the label to find out the exact year it was manufactured. 

Water Heater: Type Of Water 

Water heaters that use soft water typically have a longer lifespan than water heaters that use hard water.

This is because hard water contains minerals that will cause a scale buildup as time goes on. 

Water Heater: Fuel Type 

Here are the average lifespans of water heaters based on their fuel type: 

  • Tankless electric: 7 to 10 years 
  • Conventional electric: 10 to 15 years 
  • Tankless gas: 20+ years
  • Conventional gas: 8-12 years 
  • Hybrid or heat pump: 13-15 years 
  • Solar-powered: 20 years 

Water Heater: Maintenance 

Getting regular maintenance checks for your water heater is a great way to boost its longevity.

So, if you have not done this, it is more likely that you will need to replace your water heater sooner rather than later. 

An inspection for your water heater will include every connected pipe, putting in a new filter, checking the thermostat and valves, removing dust buildup and debris, and checking and cleaning the fuel-related heating elements, such as an ignition system. 

Water Heater: Location 

This may not seem like a big deal, but the location of your water heater can actually affect its longevity.

As previously mentioned, it is better to keep your water heater in the basement.

Meanwhile, the worst place you can store a water heater is the garage, because they are typically colder than homes and so your water heater will have to work twice as hard to heat your water. 

Water Heater: Quality Of Installation 

Whether a water heater has been installed properly or not will affect its longevity.

A water heater that has not been installed properly will have many issues and emergencies which can prove quite costly. 

Final Thoughts 

Water heaters are made up of several components, and it is important to understand how they all work, as well as the other features of a water heater such as its location, quality of installation, age, and maintenance, to ensure your home always has hot water.

Adrienne Carrie Hubbard