The difference between Electric, Gas & Solar Pool Heaters

One of the main things that people fail to realize about gas pool heaters, solar pool heaters, and electric pool heaters is that more than their differences in construction and how they work, there will be situations where one type of pool heater is better than the other!a

First up on the list, we have solar pool heaters. Just like solar panels, they are starting to grow in popularity because of their cost to operate. More specifically, they don’t cost anything to operate! Solar pool heaters basically have no moving parts so there’s nothing to fix or replace due to wear and tare. They work by transferring the heat of the sun to the water, warming it up before releasing it back to the pool.

Solar Pool heaters have one main component and those are the solar collectors. The solar collectors are usually installed on the roof of the house to make sure that they’re exposed directly to sunlight. The input side of the solar collector is attached to the pumping system (typically after the filter) and then the output side of the solar collector flows back to the pool (or through another conventional heater). That’s it! Simple, no moving parts, nothing to break, nothing to fix, just giving water a good heating up for free before routing them back to your pool!

Note: When running the pool pump at night, divert the water to bypass the solar collectors because running water through them at night will actually cool your pool water! This isn’t necessarily a bad thing because cooling down your pool water during peak summer months is actually something people do!

• Virtually Zero Maintenance
• Virtually Zero Running Costs
• Environmentally Friendly
• Long Lifespan
• Can Cool down the pool during peak summer months
• Can keep the pool or spa warm the entire season so there are no startup times
• Depending on the vendor, warranties on the solar collectors can be anywhere from 10 to 15 years

• They’re kind of expensive
• They struggle during winter, or not work at all due to ambient temperature being too low
• They work only during the day

Gas pool heaters have been around for almost as long as swimming pools have! They still are the most commonly used pool heaters (although many say not for long) because of their low initial cost and because they’ve been around for a long time. This popularity is starting to go down because of the introduction of more energy efficient pool heaters like solar pool heaters and pool heat pumps. Of course, not to mention the higher natural gas prices that we’ve been seeing recently.

Gas pool heaters take propane or natural gas and then burn them in what’s called a combustion chamber that contains copper coils. Water then passes through the coils, getting heated before being sent back to the pool. This is basically how gas pool heaters work! Simple right?

• Can be 35% to 50% initially cheaper than pool heat pumps or solar pool heating systems.
• Can be used even in the dead of winter
• Heats water very fast
• Newer, more energy-efficient models are now available in the market
• Low cost of installation

• Causes pollution (although newer models generate less)
• Shorter lifespan when compared with solar pool heaters and energy efficient pool heat pumps
• Rising costs of natural gas increases the cost of operation (which can also work the other way around, in areas where LNG is cheap then pool heating can be cheaper as well!)

There are some situations where Gas Pool Heaters can be a good idea. Given that they may become costly to operate on a constant basis, gas pool heaters are perfect for those who like to use their pools on a scheduled basis. I.e. If you like to swim at certain times at certain days, you can simply set your gas pool heater to heat up your pool based on that schedule. This means that you’re only heating the pool when you need it. But if your pool sees constant use or you would like to keep your pool warm constantly then other options may be better, like a solar pool heater or an energy efficient pool heat pump.

Gas pool heaters are also recommended for heating small spas. Since they’re quite powerful, they can easily heat up a spa in almost no time at all!

Now there is some confusion about electric pool heaters as pool heat pumps technically fall under the category of electric pool heaters since they use electricity to heat up the pool. Let’s talk about the different types of electric pool heaters shall we?

These are the simplest types of electric pool heaters. The best way we can describe the way this works is to compare it with an electric kettle. Electricity heats up the heating coils and directly heats up water in the chamber. It’s terribly inefficient, but it does heat the water pretty quick, much like electric kettles!

For electric resistance pool heaters, both the advantages, disadvantages and recommended usage situations are exactly the same as gas pool heaters. The main difference is that electric resistance pool heaters don’t create local pollution (but there is also a measure of pollution produced at the energy production source, unless that energy source comes from renewable sources).

Now this is where things get interesting. Pool heat pumps do not actually generate heat from the electricity that they consume. In a nutshell, what pool heat pumps do is that they draw in the heat from the air, transfer the heat to a refrigerant, which is then compressed to create a hot gas that heats up the water. This process is extremely efficient and can actually produce up to 5-10 times the heat when compared with the other pool heater types. Yes, this will does sound like an oversimplification simply because there isn’t enough space (and we wouldn’t want to bore you with the details) but if you’re interested in learning how a pool heat pump works then you can check it out in more detail here where we explore how energy efficient pool heat pumps work.

• They’re very energy efficient, up to 5 to 10 times more efficient than gas or electric resistance pool heathers!
• No combustion involved, so it’s extremely safe
• Less environmental impact due to its efficiency
• Extremely long life, even longer than those of solar pool heaters
• Low-maintenance
• Excellent option for constant pool heating

• Very high start-up costs
• Performance goes down during colder months (but is still more efficient than gas heaters!)
• Takes a while to heat up the pool

One thing that some pool owners do is to combine solar pool heaters with either a gas pool heater or a pool heat pump. By combining different types of pool heaters, we can actually take care of the disadvantages while still reaping all of the benefits of both! Any combination can actually work if you look at it.

• Solar Pool Heater + Gas Pool Heater = Fast Start Up while the solar pool heater maintains the temperature of the pool
• Solar Pool Heater + Electric Pool Heater / Pool Heat Pump = Accelerated heating times due to having multiple sources of heat and very low cost of maintaining temperature
• Gas Pool Heater + Electric Pool Heater / Pool Heat Pump = Fast Start Up time while the pool heat pump maintains the temperature

No matter what heating type you choose, it is always best to oversize your pool heater of choice. Having an oversized pool heater can actually reduce stress on your heaters and can heat up your pool much faster. The only disadvantage that we can think of this is the higher initial cost, but after that, it’s all smooth sailing. Having an undersized pool heater on the other hand will lead to longer heat up times, which means more expenses, and even higher stress on your pool heating elements (if using a heater with one).