What Size Natural Gas Pool Heater Do I Need

If you ask a store owner what size natural gas pool heater I need, the answers will always vary. But why is that? Turns out, heaters differ in heating capacity, and you should know your pool area before getting a heater.

The more water you have in the pool, the more heating power you need. Getting a bigger natural gas pool heater means you don’t need to wait before taking a dip.

Rule of the thumb, get a smaller pool heater if you want to keep the pool warm all the time. You can’t use a big capacity pool heater every time. The water will get too hot.

Then again, instant warming up needs a heater size equal to or more than 400k BTU.

Today, we will show you how to size a natural gas pool heater and get the best results.

What Size Natural Gas Pool Heater Do I Need

Why do you need to size natural gas pool heaters? 

Pool heaters are great for keeping the pool water warm. However, if you hardly have access to electricity or gas is cheaper where you live, a natural gas heater can help. Go for a bigger heater for instant warming of pool water. 

In the cold winters, the temperature can be a bit chilly. The only way you can turn your pool into a hot spring paradise is with a pool heater. 

Unlike electric pool heaters, natural gas ones are 50% more efficient. But you need to find the right size for the pool. When the heater is smaller, heating time increases

Generally, the heat-producing capacity of pool heaters is in BTU or British Thermal Unit. You can understand the minimum BTU requirement of the pool by calculating various factors like surface area, consult-chart, temperature shift, etc. 

What Size Natural Gas Pool Heater Do I Need? 

To size the perfect heater for your pool, try calculating these factors below. Just do the math and see the magic happen. 

Know your desired temperature boost

  • To know your desired temperature, you need to know the temperature you need. 
  • Now, determine the temperature of the pool water.
  • After you are done, subtract the pool’s thermal value from the temperature you need. 

For example, 

your pool’s temperature is 80-degrees Fahrenheit. You need to shift the temperature to 85-degrees Fahrenheit. So, you need a temperature boost of (85-80)=5 degrees. 

Determination of pool area

The area of a pool varies, depending on the brand you are using. With perfect precision, you need to determine its area. Manufacturers provide users with all the area details. However, if you don’t have one, use the formula to know the pools’ area. 

  • Rectangular Pools: Length x Width
  • Oval-Shaped Pools: Length x Width x 0.75
  • Rectangular Pools with Rounded Ends: Length x Width x 0.8
  • Complete Round Pools: 1/2 Length x 1/2 Width x 3.14

Temperature rise of pool per house

Different heaters have different heating capacities. Have you heard about the 200k BTU or the 325,000 sizes? Well, these natural gas heater sizes will tell you how fast your pool water will warm up. Follow the chart below to find out yours,

Size (BTU)27 sq. meter36 sq. meter
48 sq. meter60 sq. meter
74 sq. meter

What size of Natural Gas Pool Heater should you use?

To pick a perfect size heater, you need to determine the heating time first. If you have a pool of more than 27 m2, a 200k BTU heater will work wonders. The temperature will increase by 2-degrees per hour, making your pool water warm faster

Remember, the more BTU count, the faster your pool will heat up. Take a 400k BTU natural gas pool heater to use on any poolside you want. However, for smaller pools, avoid using the heater for too long. The temperature will increase to an unbearable level.

Then again, 200k BTU pool heater for bigger pools will just be a waste of money. The heating time will increase so much that there will hardly be any temperature difference. So, choose your gas heater for the pool according to it. Find a sweet spot between how long to set the heater and heat generation


How do you size a natural gas pool heater?

The sizing process for natural gas pool heaters is easy as pie. First, you need to determine the size of the pool. If you have a miniature pool, try out a medium to short pool heater. Additionally, using a low-performance heater for a big pool won’t do you any good either. So, get a pool heater, which warms your pool within 2-3 hours max.

How many BTU do I need to heat my pool?

Well, the BTU count depends mostly on how long you can step for the heating process and the water content. If you want a quick dip in your pool without waiting too much, get a 400k BTU heater. Then again, you can try a low powered heater, which generally takes more time to warm up.

How much gas does a 400k BTU pool heater use?

A 400k BTU gas pool heater consumes about 4 gallons of gas per hour. The gas consumption may vary if you are using a smart gas-powered pool heater.

How much does it cost to run a natural gas pool heater?

Generally speaking, the cost to run a natural gas pool heater depends on BTU count. For a 400k BTU pool heater, the cost is about 12 dollars per hour. So, per month, the price tag will range from $200 to $400.

End Note

Finding the perfect natural gas heater will vary from one pool to another. If you have a medium or big pool, a 325k BTU pool heater is the way to go. Small pools often need a low 200BTU heater max. Using a bigger pool heater on small pools will just be a waste of valuable money. 

Additional factors like storm, snow, wind, etc., also impacts the warming time of the pool. So, before you get a pool heater, check out all the expectations that can slow down your heater. 

No more today. Have a good day.

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