The main difference between gas and electric pool heaters is their power source. Gas heaters use natural gas or propane to generate heat, while electric heaters use electricity. In addition, gas heaters are generally more powerful and heat a pool faster than electric heaters. However, electric heaters are more energy-efficient and environmentally friendly.
I’ve worked as a pool technician for several years and have seen firsthand how important it is to choose the right type of heater to get the best performance and value for your money. You have to factor in several variables, including the size of your swimming pool, the local climate, and your budget.
An electric heater may be a better choice if you don’t have a gas connection or the cost of gas is too high in your area. Or a gas heater may be necessary if you have a rather large pool.
To help you decide which type of heater is best for your pool, this article will dig deep into each type of heater, what BTU ratings are all about, which factors matter for efficiency, and how you can save money. So let’s dive right in!
Gas Vs. Electric Pool Heaters: How Do They Work?
The main difference between a gas and an electric pool heater is their power source. Let’s see the components of each one and how they work differently.
Gas Pool Heater
Gas heaters can run on natural gas or propane. Natural gas is usually preferred as it burns cleaner and is more cost-effective than propane. However, both types of heaters have similar mechanisms; they consist of four key components:
- A Gas burner
- Combustion chamber
- Heat exchanger
- Circulation mechanism
When the heater is activated, the gas burner ignites the fuel and heats the air inside the combustion chamber. A fan moves the heated air to the heat exchanger, another compartment with metal pipes passing through it. The pipes absorb heat and warm the water circulating through them, eventually sending it back to the swimming pool.
Electric Pool Heater
Electric pool heaters work the same way, but instead of combusting fuel, they have a heating element powered by electricity. The element is submerged in an insulated heat-exchanging tank. Pool water enters the tank from the bottom, absorbs heat from the element, rises to the top, and circulates back into the pool.
Check out our blog “How Do Pool Heaters Work?” for a detailed explanation of pool heating systems. We have discussed the topic in more detail and explained how pool heating systems work.
Note: Don’t confuse an electric heater with a heat pump; the latter also operates on electricity but has a different heating mechanism. It uses the ambient air temperature to warm your pool’s water.
Gas Vs. Electric Pool Heater Specs Comparison
|Specification||Gas Pool Heater||Electric Pool Heater|
|1||Energy source||Natural gas or propane||Electricity|
|2||Efficiency||Typically 80-95% efficiency||100% efficiency (all electricity is converted)|
|3||Initial cost||Moderate to high||Low|
|5||Operating cost||Relatively low||Relatively high (especially on higher BTU)|
|6||Installation||Requires professional installation||The average lifespan of 10-15 years|
|7||Environmental impact||Emits greenhouse gasses and combustion byproducts||No direct emissions|
|8||Heating speed||Fast heating||Slower heating|
|9||Lifespan||It may have reduced efficiency in colder climates||The average lifespan of 5-10 years|
|10||Maintenance||Regular maintenance required||Minimal maintenance required|
|11||Flexibility||Works well in all weather conditions||It can be moderately noisy during operation|
|12||Noise Level||Wide range of control options is available||Virtually silent operation|
|13||Control options||Limited control options||Lower carbon footprint, depending on the electricity source|
|14||Size||Relatively larger in size||Smaller in size|
|15||Safety considerations||Requires proper ventilation and gas safety measures||No combustion-related safety concerns|
|16||Carbon footprint||Higher carbon footprint due to gas combustion||A wide range of control options is available|
All modern pool heaters are equipped with temperature controls, digital panels, safety features, and other amenities for convenience. However, we can consider a few key factors to decide which type of heater is right for you.
We have compared the specs of electric and gas pool heaters in the table above; now, let’s dive more deeply into how and why one might be better.
Gas Vs. Electric Pool Heater – Initial Cost Difference
The upfront cost of installing a pool heater includes the money you’ll spend on buying the heater, installation fees, and accessories. The price range for a gas pool heater is generally between $2,000 to $4,000.
If you already have gas pipelines and connections at your home, you will save on some of the installation costs. However, starting from scratch, you’ll need to purchase a gas meter, lay pipes, and make a venting system which can add $1,000 to $3,000 to the total expenses.
Electric pool heaters initially cost less than gas heaters and are available for less than $1000. They’re also effortless to install, so labor and accessories don’t usually cost much—a hardwired pool heater can be set up for less than $1000. However, electric pool heaters are only available in limited BTU.
Verdict: Electric pool heaters have a lower upfront cost.
Gas Vs. Electric Pool Heater – Long-Term Cost-Effectiveness
This one is a bit more complicated as I must consider a few variables like:
- Fuel prices
- Pool insulation
- Size of the pool
- Usage pattern
The following sections explain these points individually, but let’s look at the bigger picture here.
Fuel prices vary from region to region, but gas (or propane) is almost always cheaper than electricity. An average gas pool heater for a 20,000-gallon pool consumes less than 4 gallons of gas/propane per hour. On average, one gallon of gas is less than $4 in the USA (depending on your location & usage)—so approximately $100-$300 monthly in operation.
Since electricity is generally more expensive, electric pool heaters are also expensive to run. An electric heater will cost $500-$600 monthly to heat the same 20,000-gallon pool. However, this difference can be offset by their efficiency in certain situations, like smaller pools and spas or mild climates (discussed in the next section).
Verdict: Gas pool heaters are more cost-effective than electric pool heaters.
Gas Vs. Electric Pool Heater – Energy Efficiency
Heating efficiency refers to the ability of a heating system to convert fuel into heat effectively. In other words, heating efficiency indicates how much heat a heater can produce for a given amount of energy input.
Gas pool heaters use direct combustion to generate heat, so most input energy is converted to heat energy. Their efficiency rating typically ranges from 80% to 98%—which means up to 98% of the electricity consumed by the heater is converted into heat, and the remaining 2% is lost through the chimney or flue. The electric pool heaters, meanwhile, are available with up to 99.8% efficiency.
Typically, you’d want a high-efficiency heater to get the most heat for your money. However, electric heaters, though more energy-efficient, are less cost-effective in the grand scheme of things. Let me explain why.
The cost of one unit of electricity converting 100% to heat is more than that of one unit of gas converting only 85%. And when you factor in that gas heaters are faster, make
up for the lost heat more quickly and require less running time, they become a better choice.
Verdict: Gas heaters are more cost-effective in the long run, despite their lower energy efficheater
Gas Vs. Electric Pool Heater – Heating Speed
In colder weather, pool water rapidly loses its warmth, forcing the heater to work harder to maintain a comfortable temperature. Without sufficient heat, it takes longer, consumes more fuel, and costs more money to keep a pool warm. Therefore, heating speed is important when selecting between gas and electric pool heaters.
Typically, the heating speed is measured regarding heating capacity or BTU (British Thermal Units). BTU is the heat required to raise the temperature of one pound of water by one degree Fahrenheit. A heater with a high BTU rating produces more hourly heat and can quickly heat a pool. However, it’s a relative measure, and you have to consider the pool size and desired temperature to determine what BTU rating is optimal for your pool.
BTU = Surface area of the pool x temperature difference x 12
So, for example, if you want to heat a 20,000-gallon pool (approximately 33’x16′) from 67°F to 85°F, you’ll need a heater with an output of around 120,000 BTU/hour.
You can easily find gas heaters between 50,000 to 450,000 BTU/hr. But electric heaters are typically available for less than 150,000 BTU/hr.
This means electric pool heaters are not an option for larger pools. However, they can be used for smaller above-ground or inground pools.
Verdict: Gas heaters are faster and often the only option when it comes to heating bigger pools.
Gas Vs. Electric Pool Heater – Environmental Impact
In terms of environmental impact, electric heating is far better than gas. Although modern gas heaters are built to be efficient and safe, they still contribute to environmental pollution. Their most significant by-product is carbon dioxide (CO2), the main greenhouse gas in the atmosphere. There is also a slight risk of carbon monoxide (CO) when gas heaters are not properly maintained or serviced.
On the other hand, electric pool heaters do not produce any by-product directly at the point of use. Their environmental impact depends on the source of electricity generation. Suppose the electricity comes from fossil fuel-based power plants, such as coal or natural gas. In that case, the emissions occur at the power plant, resulting in indirect emissions. Conversely, electric heaters have a lower carbon footprint if the electricity is generated from renewable sources like wind, solar, or hydro.
Verdict: Electric heaters are more environmentally friendly than gas heaters
Gas Vs. Electric Pool Heater – Availability of Fuel and Electricity
Gas heaters need a steady gas or propane supply. In the case of natural gas, you’ll need a connection with the local utility or an external tank. For propane, you’ll need a portable or in-ground refillable tank.
Electric heaters need an outlet, so they’re much more widely available and easier to install. However, people living off the grid or in remote areas may want to consider a gas heater.
Verdict: Electric heaters are more widely available than gas heaters.
Gas Vs. Electric Pool Heater – Ease of Maintenance
Both gas and electric heaters need regular maintenance. However, gas heaters are more demanding. The burner can collect soot, filters get clogged more often, and the unit must be serviced yearly. You also need to monitor the gas line to prevent accidental leaks. But the most important thing is that neglecting these maintenance tasks raises the chances of dangerous carbon monoxide emissions.
Electric heaters also require maintenance, such as periodic filter changes, but they’re significantly less demanding than gas heaters. Plus, they usually come with built-in safety features to self-clean and alert you when maintenance is needed.
Either way, it is best to do an annual inspection by a qualified technician to ensure the proper functioning and efficiency of pool heaters.
Verdict: Electric heaters need less maintenance.
Gas Vs. Electric Pool Heater – The lifespan of the Heater
Gas heaters have a lifespan of 8 to 10 years, while electric heaters last up to 15-18 years with proper upkeep. Gas heaters have a shorter lifespan because they’re exposed to elements like fire and smoke. As a result, they need frequent repairs and replacements. On the other hand, electric heaters have insulated tanks that protect them from wear and tear.
The spare parts for gas heaters are also more expensive, so people purchase a new unit rather than invest in repairs.
Verdict: Electric heaters tend to last longer than gas heaters.
Gas Vs. Electric Pool Heater – The Size of the Pool
Big pools mean more heat is required to maintain the temperature, more fuel is burnt, more maintenance is needed, and thus more cost is incurred. As I discussed in the section on heating speed, electric heaters aren’t available higher than 150,000 BTU, and electricity is expensive. So it’s a given that gas heaters are better suited for larger pools.
Similarly, several factors ensure that only electric heaters are suitable for smaller pools:
- They’re plug-in units and don’t require venting or exhaust systems, so installing them in smaller spaces is easier.
- Electric heaters have high energy efficiency, and in small spaces, they can quickly compensate for heat loss and therefore are more cost-efficient.
- Electric heaters are mostly portable and can be moved if you want to use them in a different location.
Verdict: A gas pool heater is better for a larger pool, and an electric pool heater is better for a small pool.
Pros and Cons of Gas & Electric Pool Heaters
Gas heaters are generally the most powerful option, with high BTU outputs that can quickly raise the temperature of large pools. They also cost less to run since gas is cheaper than electricity. However, they require regular maintenance and must be ventilated outdoors. So, the installation costs can be higher.
|Natural Gas/Propane Heater|
|Fast heating||Higher initial installation cost|
|Relatively lower operating costs due to gas prices||Depends on gas or propane availability|
|Works well in all weather conditions||Requires professional installation|
|Effective for large pools or high-demand use||A wide range of control options is available|
|Wide range of control options available||Requires proper ventilation and gas safety measures|
|Compatible with existing gas lines||Requires regular maintenance and inspections|
|Can maintain temperature regardless of outdoor temperature||A wide range of control options is available|
|Wide availability and familiar technology||Larger in size compared to electric heaters|
|85% – 98% heat efficiency||Expensive repair|
Electric heaters are more affordable to install but cost more to run than gas heaters. They are also quite a bit smaller and don’t require any ventilation, making them easier to install. However, they aren’t as powerful as gas heaters and take much longer to heat a pool.
|Electric Pool Heater|
|100% efficiency||Higher operating costs|
|Environmentally friendly choice||Slower heating speed|
|Relatively easier to install||Not suitable for big pools|
|Require minimal maintenance||Not suitable for colder climates|
|Silent operation||No usage in commercial settings|
|Do not require ventilation or gas safety measures.||May require additional wiring or electrical upgrades.|
|Lower initial installation cost|
|Longer lifespan, averaging around 10-15 years.|
|Have a lower carbon footprint|
Final Verdict: Is a Gas or Electric Pool Heater Worth it?
If you love a dip in the pool and have the budget for it, gas or electric pool heaters can be an excellent investment. With heaters, you can extend your swimming season by months, especially in cooler climates.
A gas heater can keep your backyard oasis warm and inviting throughout the year with just a few adjustments to your heater settings. The initial cost for a gas pool heater can range from around $3,500 to $9,000, depending on the size of your pool. And later, a monthly energy bill of around $100 to $300 can keep them going.
On the other hand, electric pool heaters are cheap. Plus, the installation doesn’t require a gas heater’s venting or special setup, making them affordable.
Electric pool heaters are only suitable for small pools. Sometimes, they take hours to heat the water to a comfortable temperature. But if you have an indoor pool or need a quick temperature rise in your spa, an electric heater is the perfect solution.
Whatever option you decide to go with, make sure to ask questions and do your research. Get an appointment with a qualified pool professional to determine what’s best for you. Here’re your takeaways:
- Gas heaters offer higher heating capacity and lower operating costs than electric heaters.
- Electric heaters are easier to install, portable, and have no emissions or comb heater-related safety concerns.
- Electric heaters are now available with close to 100% fuel efficiency.
- Gas heaters are less fuel efficient but have a lower cost per unit of heat produced.
- Your pool’s size, climate, and desired temperature will determine the size and type of heater you’ll need.
This was all about getting a pool heater to warm up your pool. But if you don’t have a heater and still want to enjoy your pool, we have an excellent blog on how to heat a pool without a heater. Enjoy!
Frequently Asked Questions
Q: What is the difference between an electric pool heater and a heat pump?
A: Electric pool heaters and heat pumps use electricity as their power source but operate differently. Electric pool heaters use electrical resistance to warm up a metal element and transfer the heat to water through it, similar to a large electric kettle.
Heat pumps, on the other hand, extract heat from the surrounding air or ground and transfer it to the pool water using a refrigeration cycle. Heat pumps are more energy-efficient than electric heaters but may have higher upfront costs.
Q: Are solar pool heaters different from electric heaters?
A: Yes, solar pool heaters are different from electric heaters. Solar pool heaters consist of solar collectors, which absorb the sun’s heat and transfer it to the pool water through circulation. They also require adequate sun exposure and larger surface areas for effective heating. On the other hand, electric heaters use electrical resistance or heat pumps to generate heat independent of solar energy.
Q: What are the alternatives to gas or electric pool heaters?
A: Several alternative options are available besides gas and electric pool heaters. These include:
- Solar pool heaters: Solar heaters utilize the sun’s energy to heat the pool water and are environmentally friendly and cost-effective in the long run.
- Heat pumps: Heat pumps extract heat from the air or ground and transfer it to the pool water, making them energy-efficient.
- Solar covers/blankets: These covers float on the pool’s surface, trapping heat from sunlight and preventing heat loss.
- Pool heat exchangers: Heat exchangers use the heat generated by a separate heating source, such as a boiler or solar panels, to heat the pool water indirectly.
- Geothermal systems: Geothermal systems utilize the stable temperature underground to heat or cool the pool water, providing energy-efficient heating.