What Size Of Water Heater Do I Need?

If you like hot showers in the morning and warm water when you wash the dishes, you should view your hot water heater as a worthwhile investment. Every year, we receive hundreds of calls from Kansas City homeowners needing help with their water heaters. Whether it’s just not producing any hot water anymore or has even sprung a leak, your best bet is ALWAYS going to revolve around getting it fixed as quickly as possible. The longer you wait, the greater the odds are of a more serious issue occurring.

If you’ve been following along on our blog, you know that water heaters aren’t anything new to our plumbers here at Stine-Nichols Plumbing. You might even say water heater maintenance would be a part of the curriculum for plumbing 101! Having said that, we wanted to answer a common question that seems to pop up more than a handful of times throughout the year. The question I’m referring to is “What size of water heater do I need?” Depending on if you choose a tankless or storage tank will greatly impact your decision-making process. Having said that, let’s dive right in and determine what size of water heater will best fit your needs!

Going tankless?

When it comes to water heaters, your first question will be in regards to tankless or traditional storage tank options. Tankless represents the newer option and one that’s quickly taken the Kansas City market by storm. While traditional storage tank options are still widely more common, it’s safe to say tankless models are making a dent in that margin. We’ve mentioned it before on recent blog posts, but one of the major appeals of tankless is the fact that you have hot water on demand. Water is only heated when it’s needed. At the same time though, they are a little limited in the amount of hot water they can produce per minute. With that in mind, they’re likely more attractive to smaller families. Another key caveat when it comes to deciding between the two types of water heaters is the realization that tankless will require a higher up-front investment. For most though, it’s reasonable to assume that you’ll make this money back as tankless will last longer and operate at a higher rate of energy efficiency.

What size of tankless do I need?

As you’ll notice later on in this blog, sizing for a tankless water heater is much different than doing so with a storage tank water heater. When it comes to tankless, you’ll analyze the following factors:

  1. Flow Rate – As you might guess, the flow rate measures the gallons of water that can be produced per minute, also known as GPM. To calculate the flow rate, you’ll simply add the individual flow rates together for all of the fixtures you’d like to have running at the same time. 
  2. Temperature Rise – After calculating the flow rate, you’ll want to determine the temperature rise. This shows how much the water heater must heat the water before it comes out. You’ll take the desired temperature outgoing at the faucets and subtract the groundwater temperature. Here in Kansas City, our groundwater temperature tends to hover around the low to mid-50°’s F. Here’s a complete US map of groundwater temperatures from the team at Rinnai tankless water heaters.

Once you have these two factors determined for your situation, you’ll have a much better understanding of which tankless water heater will best fit your needs!

Sticking with Traditional Storage Tank Models?

As briefly mentioned above, the traditional storage tank water heaters are certainly the much more common option! In contrast to tankless water heaters, storage tank ones have an insulated tank. In this tank, the water heaters store hot water until a faucet is opened and it’s needed. It comes at a cheaper price tag than it’s tankless alternatives as well.

What size of storage tank do I need?

The sizing question becomes a bit more literal when it comes to storage tank water heaters. 

Household Size – There are a few characteristics that you’ll want to analyze from the forefront, with the first of these being household size. Here we have an easy determining factor that will give you a rough estimate of the correct size.

  • 1 to 2 people will require a tank of at least 30 gallons.
  • 2 to 4 people will require a tank of at least 40 gallons.
  • 3 to 5 people will require a tank of at least 50 gallons.
  • Once you get above 5 household members, it might be wise to look into an 80-gallon electric tank.

Space Occupied – One of the nicest things about tankless water heaters is the fact that they don’t take up a whole lot of space. They can easily be attached to the wall. On the flipside, storage tank water heaters are going to need a little bit more space! For most Kansas City residents, your best landing spot is going to be either the garage or basement. All in all though, no matter what size of tank you choose to have installed, just make sure you have enough room for it!

First Hour Rating – Commonly referred to as the FHR, this statistic tells you how much hot water can be produced in a one-hour time period. To determine if a particular water heater is big enough for your household, you’ll want to add up the highest demand you could possibly have in that period of time. Say two showers occupy an average of 20 gallons of water each, the dishwasher is started with an average of 6 gallons of water and the washing machine uses 25 gallons. In that one hour time period, you’re looking at around 71 gallons of water. While household size is a terrific starting point, the truth is some people simply use more water than others. As a result, the first hour rating can be a great tool to utilize. Additionally, most average gallons of water per action (starting the washing machine, brushing teeth, etc.) can be found with a simple Google search.

Fuel Source – The final question you’ll ask yourself is what fuel source do you plan on utilizing. Gas, propane, or electric. While this won’t be as impactful as the previous points, it can be helpful when it comes time to swipe the credit card. Particularly, in today’s market where there’s certainly no shortage of manufacturers out there, any tools to simplify the buying process are well worth it!

Need Help?

We hope this sizing guide has provided you with a general understanding of what all goes into choosing the perfect water heater! Your next step after this would be determining the brand that’s going to provide you with the most bang for your buck. If you’re ready to move forward with a potential hot water heater project for your Kansas City home, give your friends at Stine-Nichols a call at 816-348-3481. We’re more than happy to provide a free quote for projects of all sizes and will let you know which water heater works best for you and your family!

Want to save a few bucks? Head over to our coupons page on our website. We regularly post new deals to ensure our customers get the best deals in town. Considering water heaters work much harder throughout the cold Kansas City winters, we have a special up there right now for all new water heater installations. Tankless or storage tank, it all counts! Just make sure you mention the special to Doug or Jim when scheduling your project and you’ll be good to go!

By |2020-01-15T15:17:35-06:00January 15th, 2020|Residential Plumbing|