TL;DR: How much it costs to heat a pool is two separate bills: what the heater costs to buy and install, and what it costs to run each month. The running cost depends on your pool’s size, how many degrees you add, how long you hold them, whether the pool is covered, and your electric rate. This guide gives the method to work out your own number, how long heating really takes, and the cheapest ways to do it.
Search for the cost to heat a pool and you will find forum threads of strangers comparing electric bills, because nobody can give one honest number for every pool. What can be given is the method, so you can put your own bill into it. This post covers the cost side and the time side. If you are still deciding which kind of heater suits a Southwest Florida pool, our guide on whether you need a pool heater in SWFL compares the types, so we will not repeat that comparison here.
Liquid Concepts Pool Service has been family-owned in Fort Myers since 2010. We install and service heaters through our pool heating work, and we will tell you plainly when heating is not worth it for how you use your pool.
How much does it cost to heat a pool?
The monthly cost to heat a pool equals the heat your pool needs, divided by how efficiently the heater makes it, multiplied by your price for that energy. Pool size, target temperature, hours of use, cover use and your utility rate all change the result, which is why published averages rarely match any real pool.
Read that as four questions you can answer about your own pool:
- How big is the pool? More water means more heat needed for every degree. Double the volume and you double the energy to raise it by the same amount.
- How many degrees are you adding? A pool that only needs a small lift on a cool morning costs far less than one being pushed up from a cold snap.
- How long do you hold it? Keeping a pool warm all season is a different bill from heating it for a weekend.
- How much heat escapes? Wind, an uncovered surface and shade all change how fast the water gives its heat back.
Fort Myers helps with the third and fourth questions. When it does turn cool here, a heater is usually closing a modest gap, not climbing from near freezing. That is a mechanism, not a promise: a windy, uncovered pool can still lose heat quickly.
Florida Power and Light publishes a pool heating calculator that assumes a heat pump efficiency (COP) of 5 and an electric cost of $0.12 per kWh, applied to a 14 by 28 foot pool over the months of November through April. Treat those as the calculator’s own inputs, not as your rate or your pool. A COP of 5 simply means the heat pump delivers five units of heat for each unit of electricity it draws. Your actual rate is printed on your bill, so swap it in.
Running cost versus buying cost: two separate bills
Buying a heater is a one-time cost set by the unit’s size, the electrical and plumbing work around it, and installation. Running it is a recurring cost set by your electric rate and your habits. A cheaper unit is not automatically a cheaper decision, because the two bills pull in different directions.
This is where most people get stuck. A quote tells you the first number and says nothing about the second, and the monthly bill arrives months later. Ask for both before you commit.
For the purchase side, here is what moves the price:
- Heater size, matched to the pool’s volume and how fast you want it to heat.
- Electrical work, because a heater typically needs its own circuit and a proper connection. Your installer confirms what yours requires.
- Plumbing, because the heater sits in the water line and the pump must supply the flow it needs.
- Installation and commissioning, including testing that it heats properly.
We do not publish a fixed heater price. Equipment, site conditions and the existing pad all decide it, so we give you a clear estimate first, and no work is performed without your approval. The same no surprises approach runs through our flat-rate weekly pool service, from $145 per month with no contracts. If the pump that feeds the heater is old, it is worth looking at equipment installation and upgrades at the same visit, and our post on whether a variable speed pump is worth it explains why the pump is part of the heating bill too.
How does a pool heat pump work?
A pool heat pump does not burn anything to make heat. It pulls warmth out of the surrounding air with a refrigerant cycle and transfers it into the pool water as the pump circulates it through the unit. Because it moves heat instead of creating it, its running cost depends mostly on your electric rate and how long it runs.
That also explains a behavior worth knowing: a heat pump works from the air around it, so its output tracks the weather. On a mild day it does more for each unit of electricity. Which kind of heater fits your pool is a separate question, and we cover it in the heater type guide.
How long does it take to heat a pool?
Heating time is the heat the water needs divided by the heater’s rated output, less whatever the pool loses to air and wind meanwhile. A larger pool, a bigger temperature gap and a cool, windy night all lengthen it. No single hour count fits every pool, so use the method below.
The question people usually mean is how long it takes for a pool to heat up from cold to swimmable. These are the numbers that decide it:
- Pool volume. Time rises in step with the amount of water.
- Degrees to add. Each extra degree is more heat to deliver.
- The heater’s rated output. It comes from the manufacturer’s data plate and rating sheet. Ask for the output rating at the air temperature you actually expect, because a heat pump’s output depends on the air.
- Heat loss while heating. An uncovered pool in wind gives heat back to the air as fast as the heater adds it.
A heat pump adds heat steadily rather than quickly, which suits a pool you hold at temperature rather than one you heat on demand for tonight. If you want a warm pool for a specific day, say so when you ask for a quote, because that changes how a heater should be sized.
How long does it take to heat a 10,000 gallon pool?
For a 10,000 gallon pool, heating time equals the heat needed to raise those 10,000 gallons by your target number of degrees, divided by the heater’s rated output. Take both figures from your own pool and the heater’s rating sheet. A rated output twice as large halves the time, and a cover shortens it further.
We are deliberately not quoting an hour count here. Any figure that ignores your rated output, your starting temperature and the weather on the night is a guess presented as a fact. With the heater model in front of you, the rated output is on the data plate and the arithmetic above is the rest of it. Our pool inspection also documents the condition of the equipment you already have, which is a sensible first step before sizing anything new.
Work out your own pool heating bill in four steps
You can estimate your heating cost with your electric bill, your heater’s rating sheet and a calendar. The aim is a range you trust, not a number copied from a stranger.
- Find your rate. Read the price per kWh from your latest bill. Use that, not the calculator’s default.
- Find the heater’s efficiency. For a heat pump this is its COP rating on the manufacturer’s sheet. A higher COP means less electricity for the same heat.
- Estimate your heating hours. Count the weeks you will actually heat and whether you hold the temperature or heat only before swimming.
- Run it twice. Calculate once with a cover on the pool at night and once without. The gap between the two answers is the most useful number in the exercise, and it costs nothing to learn.
FPL’s calculator lets you tick a box for a nightly pool blanket, which tells you the utility itself treats cover use as a variable that changes the answer. Run your estimate through it, then compare it with a quote.
If a number surprises you, it is usually one of two things: heating hours were longer than you pictured, or the pool was uncovered. Before you decide the heater is too expensive, check that the pump is not running far longer than necessary, which our post on how long to run your pool pump in SWFL covers. A pool automation system can also schedule the heater so it runs only when you plan to swim, and whether automation is worth it is its own question.
What is the cheapest way to heat up a swimming pool?
The cheapest way to heat a pool is to stop it losing the heat it already has. Covering the surface at night, blocking wind, and setting a lower target temperature all cost little or nothing. Add a heater only for the gap those steps cannot close.
This is the counter-commercial point most heater pages skip, because they sell heaters. Water gives heat up at the surface: evaporation and wind pull warmth out of an uncovered pool, and a heater then spends electricity replacing it. Slowing that loss first means a smaller heater works less, or that you need none at all on a mild week.
The cheapest steps, in order:
- Cover the pool whenever nobody is swimming. It is the one measure that works on a pool with or without a heater.
- Lower the target. Every extra degree you hold costs more to maintain, so set the temperature you will actually use.
- Block the wind where you can, and check whether a tree is shading the water in the hours the sun is lowest.
- Heat on a schedule, not all day, so you are not paying to warm water nobody is using.
What is the cheapest way to heat an inground pool?
The same order applies: reduce loss, then heat only the remaining gap. An inground pool has its walls surrounded by earth, while an above-ground pool has walls open to the air, so the exposed surface and the wind matter most for inground pools. Cover first, schedule the heater second.
We hold a Florida Certified Pool/Spa Contractor license, number CPC 1459893, and we size heaters to the pool in front of us. If a cover and a lower target do the job, we will say so before selling anything.
How do you heat a pool without a heater?
You can heat a pool without a heater by capturing more of the sun and losing less overnight. A solar cover over the surface, a sunnier position, less shade and wind protection all help, and none needs electricity. They raise the temperature gradually, not on demand, so plan around the weather.
These methods lean on sun and on keeping heat in rather than adding it. They work best for a modest lift, such as taking the edge off a cool week. They will not match a heater on a cold front, and we would rather you know that before you buy a cover expecting a heater’s performance.
How to heat a swimming pool for free
The free options all work on the same principle: keep the heat you already have. Remove the leaves and floating debris that block sun from the water, trim back any shade you control, take the cover off during the sunniest hours and put it back at dusk, and lower your target temperature to what you will actually use.
How fast does a solar cover heat a pool?
A solar cover heats a pool slowly and steadily. Its speed depends on how much sun reaches the surface, how big the pool is and how cool and windy the weather is. A cover is most effective at holding warmth overnight, which is why it works best alongside a heater, not as a replacement.
There is no honest hours or degrees-per-day figure to give without your pool’s size and conditions. A cover’s biggest contribution is on the night side: it slows heat loss, which lowers the bill for any heater you add later.
Is heating your pool worth it?
Heating a pool is worth it if you will swim in the cool weeks and the cost is acceptable once you have run your own numbers. It is not worth it if you swim mostly in the warm months, rarely use the pool in winter, or are happy with a cover and a lower temperature.
Be honest about how you use the pool. Heating suits people who swim for exercise, who host family and guests in winter, or who rent the property. It pays least for a pool used from spring through fall. We are a service and installation company, which means we have no reason to push a heater on a household that would be better with a cover. Our post on repair versus replacement for pool equipment takes the same view when an existing heater is failing: sometimes the cheaper fix is the right one.
A heated pool also needs more attention to chemistry, because warmer water is harder on sanitizer and balance. If pH drifts, see how to lower pH in your pool. Our weekly pool service covers the routine testing and balance.
Frequently asked questions
Does a pool cover change what a heater costs to run?
Yes. A cover slows the heat the pool loses to the air overnight, so the heater has less to replace the next day. It is the cheapest change you can make, and running your estimate with and without a cover shows how much of your bill depends on it.
Should I leave the heater running or turn it on before swimming?
It depends on how you use the pool. A heat pump warms water gradually, so planning ahead usually works better than trying to heat on demand. A thermostat or an automation schedule lets you hold a comfortable temperature without heating hours nobody uses.
Does a heated pool need more chemical attention?
Yes, a little. Warmer water changes how sanitizer and pH behave, so testing matters more in the weeks you heat. Regular service means the water is tested and balanced on each visit, and a drifting pH can be corrected before it affects equipment.
Who sizes and installs a pool heater in Fort Myers?
Liquid Concepts installs and services pool heaters across Fort Myers, Cape Coral, North Fort Myers, Estero, Bonita Springs and Lehigh Acres. We size the unit to your pool and equipment pad, check the circulation system supports it, and give you a written estimate before work begins.
Get a written heating estimate in Fort Myers
If you want to know what heating your pool would cost to buy and to run, we will walk through both bills with you, using your pool and your electric rate, and we will tell you if a cover is the better answer. Liquid Concepts has been family-owned since 2010, founded by Jonathan Kaplan, with three generations and 60+ years of combined pool-care experience and 70+ five-star reviews from owners across the region.
We serve Fort Myers, Cape Coral, North Fort Myers, Estero, Bonita Springs, Lehigh Acres and Fort Myers Beach. Call (239) 526-8830 or use our contact page. You can read what other owners say on our reviews page, browse our services hub, or see what pool service costs in our Fort Myers pricing guide.