A new pool heater can lower your energy bill, but only when your current heater is old and inefficient and you heat the pool often. If your heater is fairly new or you only fire it up a few weekends a year, the savings are usually small and a replacement will not pay for itself through the bill alone.
This guide covers when an upgrade cuts your gas or electric costs, when it does not, and how to estimate your own payback before anyone quotes you a new unit. If you are weighing a fix against a new heater for other reasons, our guide on whether to repair or replace a pool heater covers that decision.
Will a new pool heater lower my energy bill?
Sometimes, and the size of the drop depends on two things you can check yourself. The first is how efficient your current heater really is. The second is how much heating shows up on your bill today.
A heater that burns a lot of fuel to deliver its heat has room to improve. A heater that is already close to modern efficiency does not. And if heating is a small slice of your bill, even a big efficiency jump only trims a small number.
When I look at an older heater, I start with its age, its rating plate, and how it lights. Then I ask how often the owner actually heats the pool. Those details predict the savings better than any brochure.
How much more efficient are new pool heaters?
Less than most people expect for heaters built in the last decade, and more for the older ones. According to the U.S. Department of Energy's 2023 final rule on consumer pool heaters, gas-fired pool heaters made since April 16, 2013 must reach at least 82 percent thermal efficiency.
That means a heater installed in the last ten years or so was built to a federal floor that is close to many units sold today. Swapping it out for efficiency alone moves the needle only a little.
The same DOE rule changes the math again for heaters made on and after May 30, 2028. It switches to a new rating called integrated thermal efficiency, which also counts energy used while the heater sits idle. DOE notes that standing pilot lights burn fuel even when the heater is not in use. It also sets the first federal efficiency standard for electric pool heaters.
When does a new heater actually cut the bill?
The savings are real when several of these line up at once:
- The heater was built before the 2013 federal standard, or its rating plate shows a lower efficiency than today's units.
- It uses a standing pilot light that burns gas around the clock, even when nobody is swimming.
- Scale, soot, or corrosion inside has made it work harder than when it was new.
- You heat the pool often, so heating is a large share of your gas or electric bill.
- You are switching to a heater type that better suits how often you swim.
When most of those are true, a new heater uses noticeably less fuel for the same water temperature. When only one is true, the drop is usually modest.
When won't a new heater save much?
A new heater saves little when the old one is already efficient, or when you rarely use it. DOE estimated the average pool heater lifetime at about 11 years in the same 2023 rule. A heater well inside that window often has decent efficiency left.
Use is the bigger factor. If the heater runs a handful of weekends a year, heating is a small line on your bill. Cutting a small line by a fair percentage still leaves a small dollar figure.
In that case, I tell owners to keep the heater until it needs a major repair. The decision then belongs to the repair-or-replace question, and efficiency becomes one factor among several.
How do I estimate my own savings and payback?
You can get a solid estimate with your utility bills and your heater's rating plate. Here is the method I walk owners through:
- Find what heating costs you now. Compare gas or electric bills from months you heated the pool against similar months you did not.
- Find both efficiency ratings. Your current heater's rating is on its label or in its manual. The new unit's rating is on its spec sheet.
- Work out the fuel savings. Divide the old efficiency by the new one, then subtract the result from 1.
- Multiply that percentage by your yearly heating cost. That is your rough yearly saving.
- Divide the extra cost of replacing now by that yearly saving. That is your payback in years.
Here is an example with made-up round numbers. Say your old heater runs at an effective 70 percent and the new one is rated at 84 percent. Then 70 divided by 84 is about 0.83, so the new heater needs roughly 17 percent less fuel for the same heat.
If heating added $600 to your bills last year in this example, 17 percent is about $100 a year. Compare that to the price gap between a repair and a new heater. If the payback runs longer than the heater's expected life, efficiency alone is not a reason to replace it.
Treat the old heater's rated efficiency as a best case. A dirty or scaled heater can do worse than its label, which would make the real savings a little larger.
Does switching to a heat pump change the math?
Yes, because a heat pump moves heat from the air instead of burning fuel. The DOE rule notes that California's Title 20 appliance efficiency regulations have required heat pump pool heaters to average a coefficient of performance of at least 3.5 since 2003. DOE also notes many heat pump pool heaters are rated at 6.0.
A coefficient of performance of 3.5 means about 3.5 units of heat for each unit of electricity used. That makes a heat pump efficient per unit of heat. But you pay for electricity instead of gas, so your bill depends on both rates and on how you heat.
I will not repeat the full comparison here. Our gas vs electric pool heater guide covers heat-up speed, climate, and running costs side by side. For the payback math above, use your electric rate and the heat pump's rating in place of the gas figures.
What lowers a heating bill before you buy anything?
A pool cover usually does more for the bill than a new heater. In its 2023 pool heater rule, DOE assumed a pool cover can save up to 50 to 70 percent of overall pool heating energy. That is a bigger cut than most heater upgrades.
A few other low-cost habits help too:
- Cover the pool every night and any day nobody swims.
- Set the thermostat to the lowest temperature your family finds comfortable.
- Turn the heater off between swim days instead of holding the water warm for days at a time.
- Keep the heater clean and serviced so it runs closer to its rated efficiency.
Try these first. If the bill is still high and the heater is old, the case for a new one gets stronger. If the heater has a fault, pool heater repair may get it running efficiently again for less than a new unit.
The questions Long Beach pool owners ask most about heaters and energy bills, answered plainly.
Want help running the numbers on your heater?
You should not have to guess whether a new heater will pay for itself. At Adam's Pool & Spa, I can check your heater's age, rating, and condition, then walk through your bills with you using the method above. We serve Long Beach and the surrounding neighborhoods, and we are Jandy Certified and a Pentair Expert Installer. If a repair or a pool cover is the better move, that is what I will tell you. Schedule a visit and we will start with the honest version.
Adam is the founder, owner, and lead technician of Adam's Pool & Spa, serving Long Beach and surrounding LA County for about fifteen years. He is Jandy Certified and a Pentair Expert Installer, and he built the business on education-first, anti-pressure service, including the "Pool School" session every new client gets.
