04 Apr

Water Heater Sizing Explained In A Way That Makes Sense

  • Karen Mares
  • Comments Off on Water Heater Sizing Explained In A Way That Makes Sense

The time has come to start shopping for a new water heater. At Casey’s, we proudly recommend and install American-made Bradford White Water Heaters. We believe they are the best in the business. But, as you go about choosing your new water heater, what capacity do you need? Water heater sizing is one of our most frequently asked questions when our plumbers consult with customers.

At Casey’s, we want to arm you with the best information possible BEFORE you are in an emergency situation, so we’re here to break down the basics of water heater sizing for you.

Water Heater Sizing: What Do I Need?

Here are the basic things to ask when you are deciding on the size of water heater you need to purchase:

  1. What is our peak demand? When looking at water heater sizing for your home, calculating a rough estimate of your demand will go a long way toward figuring out the size of water heater you need. To determine your peak demand, find out:
    • What time of day is hot water being used the most in your home? Keep in mind the number of people living in your home as well. 
    • What activities are using the hot water during this peak time of day?
      • For example: a shower uses approximately 10 gallons of water. If you have three people in your home taking a shower between 6:00 am and 7:00 am, 30 gallons of hot water was used during that time period. If you wash your hands during this time, that will add approximately four gallons to that peak demand time frame. 
      • The above example would mean that a water heater model with a 34-38 gallon first hour rating would be appropriate for your level of usage.
  2. Look for models with a capacity within one or two gallons of your peak demand. When looking at water heater sizing options, Bradford White’s website provides a handy, interactive guide to determining the right size water heater for your home. Find it here: Bradford White Right Spec Sizing Guideline.

The Casey’s Difference

Why purchase your home’s water heater through us? Quite simply, our warranty is the best in the business. We offer three different heating systems: Standard, Deluxe or a Premiere system.

  • With our Standard System, you’ll get not only the average six year on parts but we cover the labor for six years as well!
  • Our Deluxe System comes with an expansion tank (shock absorber for water heaters), a 10-year parts AND labor warranty and 10 years of service. In order to ensure an efficient water heating system, we come out every year to adjust, maintain and even replace if needed – whatever the system may need during this time frame.
  • The Premiere System includes everything that’s included in the Deluxe System as well as a water alarm that sounds in case of a leak and the warranty is for life! That’s right, with a premiere water heating system from Casey’s Plumbing, we’ll service that water heating system for as long as you live in the home. And you can transfer this warranty once, for up to 10 years.


The average water heater warranty is typically only a year, and that doesn’t always include labor. At Casey’s, we’ll take care of your investment as if it were our own home. We are a local, family-owned business, and we want to be the company you think of when you need plumbing help. 

Westside: (Beaverton, Tigard, Lake Oswego) 503-620-9111

Eastside: (Troutdale, Gresham, West Linn) 503-253-0030

water heater sizing

About Karen Mares

A Portlander born and raised, Karen lives in Southwest Portland with her husband and children. Karen has kept journals throughout her life, and she began her personal blog, Random Thoughts From A Suburban Mom in 2007. She hasn't stopped writing online since, channeling her passion for words and information into writing and communicating through social media and blogging.