If you’re surprised with an icy cold shower one morning, it may be time to get new heating equipment. When purchasing a new water heater, you’ll want to make sure that it’s the right type and size for your home.

As with any major home improvement, you should first do your research and gain as much knowledge as you can in order to make the correct choices.
Here’s an easy and simple guide to help you determine the right size of water heater for your home from a trusted heating service provider.
How Do You Know If Your Heater Is Undersized?
With an undersized heater, you won’t get enough hot water. This can also cause the water to be too hot, resulting in condensation and pilot flame outage because of water dripping onto the flame. You’ll know your water heater is too small if there’s heavy condensation, early tank failure, rust chips on the burners and flue tubes or not enough water. Keep in mind that proper sizing also involves the right kW to heat the water, the correct pipe size to deliver the needed flow and output, amperage, drain pipeline, recovery rate, amperage, vent to handle the total BTU input, recovery rate, expansion tank, electrical fusing and the air used from the given opening size.
When your heater is too small or large, it can cause issues that will lead to early deterioration of the equipment. An undersized heater may also not be eligible for a warranty. Meanwhile, if you have the right size of water heater, the burner and other components won’t need to work as hard, meaning there’s less strain put on them. This can result in a longer lifespan. As a leading provider of furnace installation services, you can count on Bill Reynolds Heating & Air Conditioning to help you choose the best water heater for you and your needs.
What Size of Heater Do You Need?
Many consumers make the mistake of purchasing a water heater based on the size of the storage tank. You must take into consideration the peak hour demand capacity or First Hour Rating. You’ll find this information on the Energy Guide label or brochure. It may also be available under the specifications, features or performance section of the manufacturer’s website. If the rating of your water heater matches the peak hour demand, your water heater will meet your hot water needs.
First Hour Rating pertains to how much hot water a unit can produce. For instance, the First Hour Rating of natural gas heaters range from 40 to more than 100 gallons. It’s stated in gallons, and is the result of combining the amount of usable hot water stored in the tank and how many gallons of usable hot water your heater can make in one hour. For example, if you have a 50-gallon natural gas heater and it stores 42 gallons of usable hot water and produces 45 gallons of usable hot water in the first hour, its First Hour Rating is 87 gallons.
To find out exactly how much hot water you need, you’ll need to calculate how much you normally use during your busiest hot-water-using hour. However, if you only need a rough estimate of the size that you need, there are guidelines you can follow. If there are one or two people in the house, 30 to 40 gallons is ideal, while you’ll need up to 50 gallons if there are three occupants. For homes with three to four family members, 50 to 60 gallons are recommended. And if more than five people are using the heater, 60 to 80 gallons is best. If you’re still unsure about how much hot water you need, you can always contact Bill Reynolds Heating & Air Conditioning with your concerns. You can rely on us for your air conditioning repair needs as well.
In one-bath residential homes or apartments, you’ll usually see 30-gallon units and 40-gallon ones in two-bath residential homes. For three-bath residential homes or three applications, 50 gallons is usually enough.
Keep in mind that the aforementioned numbers are simply general guidelines, and they may not exactly meet your hot water needs. For instance, a house with four people may do just as well with a 30-gallon tank, but it may also not be enough for a household of two, depending on their needs.
The size of the heater you need depends largely on your hot-water-using habits. For example, if you consistently use three or more hot water appliances within the same hour, your heating service provider might suggest getting a larger water tank than what’s in the stated guidelines. However, if you don’t use as many hot appliances within the same hour, you may need a smaller tank.
Essential Things to Consider
Two of the most important things to consider when choosing a water heater are storage or capacity and heat input. It’s essential to choose the right equipment size, especially when you need a large amount of water within a short period of time. On the other hand, the heater recovery rate matters more if the peak usage period is longer.
Heater and furnace installation experts suggest purchasing a heater with the highest Energy Factor (EF). EF pertains to the efficiency of a heater. ENERGY STAR® heaters usually have a higher EF, which lets you save more on energy costs and get rebates through government incentives. However, you’ll get a lower EF with larger storage tank models. The lower the EF, the higher the operating costs will be.
Another thing to be mindful of when selecting a new water heater is the size limitation, such as the diameter and height of the unit. There are different kinds of models like short, lowboy, tall and tabletop, which can fit just right in the room where it will be placed.
For quality water heater installation services, turn to Bill Reynolds Heating & Air Conditioning. We also specialize in air conditioning repair and replacement services. Call us at (440) 946-7863 or fill out our contact form to get a free quote.
Thank you for pointing out that it is a good idea to find a water heater that has a high EF rating. My wife and I want to purchase a new water heater. We have a lot of kids that use a lot of water, so a new heater will help us save money.
My parents own a few vacation rental properties, and they want to upgrade their HVAC and plumbing systems to increase their prices. That’s why I think they’d benefit from reading your insight about understanding how to choose the right-sized water heater, so I’ll share your article with them right now. Thank you for the advice on calculating how much water we use before buying a water heater.