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Choosing the Best Pool Heater for Virginia Winters

There’s a lot that goes into determining what heater will work best for your pool. Your choice depends on a range of factors, and is only made more difficult with the colder temperatures of Northern Virginia. We’ve broken down the decision process into its key factors to help you decide what works best for you:

Size of Your Pool

The size of your pool is the first thing to consider. Put simply, the larger your pool is the harder it’ll be to heat. Pool heaters are measured in BTUs (British Thermal Units); the larger the heater, the more BTUs it will put out.

One BTU is equal to the amount of work needed to raise the temperature of one pound of water by one degree Fahrenheit. You’ll need a 200-300 BTUs heater for 10,000-20,000 gallons, 300-400 BTUS for 20,000-40,000 gallons, and 400+ BTUs for 40,000-80,000 gallons, which most often describes commercial installations. In most cases, for typical residential swimming pool sizes, the larger heaters heat water faster and help control your costs.


The location your pool is in is also important. Is your pool in direct sunlight? Is it completely in the shade? Maybe a combination of both as the day unfolds? This will contribute to how large your heater needs to be. The sun will help heat your pool and keep in warm, lessening the load on your heater. If your pool is in the shade, you may consider a bigger heater in terms of BTUs.


In Northern Virginia the winters can be frigid. This is something you’ll have to take into consideration when picking a heater. You’ll need to determine when you will be heating your pool — will you be using your heater to get your pool warmer in the summer or will you be using it to swim in November? Certainly, pool heaters extend the swimming season as much as you would like.

Keeping a pool a few degrees warmer in the summer doesn’t take nearly as much energy as warming it up to 75 or 80 degrees when it’s starting in the mid-60s. Similarly, keeping your pool heated constantly as opposed to heating it a few days a week will allow you to use a smaller heater, because less power is used at once (to raise the temperature); instead, the heater will just be maintaining the temperature.

Altitude is another factor. Different heaters are built for different altitude ranges. Virginia is below 6,000 feet, with the majority of the state being below 1,200 feet, so finding a heater built for higher altitudes won’t be a major concern.

Solar Covers

A solar cover will help you reduce the amount of energy required to heat your pool. By covering the surface of the pool, a pool cover will trap heat in, keeping the water temperature the same for longer periods. Using one can also reduce your overall operating costs.

Type of Heater

For both above ground and in-ground pools, there are three types of heaters to choose from: natural gas, propane, and heat pumps. In the order of most to appropriate for Virginia weather, here’s a basic breakdown.

Gas Heaters

These heaters run on either natural gas or propane and heat your pool quickly. They produce no emissions and are the best option for heating pools in colder environments, like Northern Virginia. Although gas heaters require a lower initial investment, they can be more costly to operate depending on usage and utility prices in your area. Propane gas heaters are much the same as natural gas heaters with few differences in operational expense.

Pool Heat Pump

If you want to heat your pool in the summer, late spring, and early fall months — but not the winter — a pool heat pump might work for you. These heaters are effective when operating with an outside temperature above 40 degrees Fahrenheit.


Looking for more information on pool heaters or other pool-related products? Give us a call at (571) 918-0635 or fill out our online contact form to receive expert guidance and support from the pool supply professionals at Anthony and Sylvan.