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How To Heat A Pool: 9 Heating Methods (Cheapest First)

So you’ve got a dilemma.

You want to heat your swimming pool, but you don’t want to spend a ton of money doing it. 

The struggle is real.

There’s no definitive way on how to heat a pool, so we’re throwing at you every conceivable method available that can raise the water temperature for a more comfortable soak.

The Challenges Of Heating A Pool

Heating a pool can be a tricky thing when you consider the many shapes and sizes pools come in. A method that warms a small pool might not necessarily work as well with a large pool.

The climate where you live can also affect the pool water’s temperature. Warmer climates require less heating than places where the weather is cold and windy.

Some pool owners aim to keep their weather warm all-season long, while others are perfectly content with raising the temperature only when they’re having a backyard bash.

Combining heating methods and various equipment can also be advantageous, such as using a gas heater to quickly raise the pool’s temperature, and then maintain that heat using a secondary heater.

And of course, getting the most bang for your buck is important, so you’ll want to go with a heating option that meets your budget requirements.

How To Heat A Pool (9 Methods)

The following methods are ordered from cheapest to most expensive, considering a combination of cost factors from initial outlay to installation, as well as the ongoing running costs.

1. Liquid Solar Covers/Blankets

Liquid solar covers provide similar benefits as a traditional pool cover, and all you have to do is pour it into your pool. However, they don’t necessarily heat the water, but rather keep heat from escaping.

Liquid solar covers are invisible and save you time and space when compared to the demands of pool blanket use and storage. It’s made from a single molecule, high-fat alcohol, which floats on the surface of the water.

When the pool is in use, the cover is dispersed in the water. Once the water becomes still the solar cover molecules reassemble like the T-1000, protecting the surface of your pool from heat loss and evaporation.

A 32 oz. bottle of solar cover costs around $25 and will give you around 2 months worth of use when adding to the pool once a week. However, depending on how often you use your pool, it may have to be added more frequently. Still, this is a remarkably cost-effective way to keep heat locked into your pool.

Pros:

  • Cheapest way to keep your pool warm
  • Keeps heat from escaping through the surface of the water
  • Easy to add to the water
  • Bottle is easy to store
  • Single bottle can last up to 2 months 
  • Chemicals used are safe for swimming in

Cons

  • Doesn’t actually add heat to the pool
  • Solar cover will lose effectiveness in windy conditions
  • Has to be added weekly
  • Has to be added even more frequently if pool is used often

2. Black Hose Method

The black hose method is essentially a DIY solar pool heater. 

Why a black hose and not a traditional green garden hose? Black absorbs more sunlight and the tubing is going to act as the heater.

The hose needs to be coiled up in a spiral and positioned somewhere where sunlight is constant. Some people go so far as to mount this 100 foot coil on a pallet so it’s easy to move around (and looks cleaner). You can also use extension hoses to and from the coil, depending on how far it’s positioned from the pool.

Using a submersible pump placed in the shallow end, attach one end of the tubing to it. This will allow it to pump out the pool water, injecting it into the coil. As it flows through the heated tubing, the water warms up. Place the other end of the coil in the pool so the warm water is emptied into it.

While it sounds a bit hacky, this is actually a pretty clever heating system and costs pennies when compared to automatic heating systems. Aside from the materials, electricity for the pump is the only cost you will incur. 

Materials costs include: a submersible pump ($30 – $400), 50 to 100 ft. of black irrigation tubing (approximately $10), and barbed fittings on the tube ends. If you can’t find irrigation tubing, a black garden hose will work just the same but costs anywhere from $30 to $75.

Pros:

  • One of the cheapest heating methods
  • Solar powered 
  • Eco-friendly 
  • Zero installation costs
  • Only requires electricity to run
  • Maintains pool heat level well
  • Can raise water temperature over 20°F

Cons

  • Heater that requires DIY know-how
  • Dependant on amount of sunlight
  • Can be an eyesore
  • Takes up a pallet size (48” x 40”) worth of room
  • Submersible pump can be expensive
  • Line running in and out of pool can be a trip hazard

3. Solar Covers/Blankets

A solar cover or blanket is essentially a huge sheet of thin plastic that you place on your pool water when not in use, often resembling bubble wrap. They also come in various shapes, sizes, thickness, and colors.

It heats the water by capturing heat from the sun, directly transferring it to your pool. The impact this has on your water largely depends on the size of the cover (and pool) and the amount of direct sunlight it’s exposed to.

This alone might not be enough to make a meaningful difference in your water temperature, but solar covers also prevent heat loss through evaporation which happens to be the biggest cause of heat loss from a pool, especially at night.

A solar cover will set you back anywhere from $20 for a small strip, to several hundreds of dollars for a large sheet to cover a large pool. Of course, there aren’t any installation or running costs to worry about.

Pros:

  • One of the cheapest ways to heat your pool
  • Very good at retaining existing heat in your water
  • Reduces cost for more expensive heating methods
  • Covers available for both inground and above pools
  • Prevents the sun from burning through your chlorine
  • Prevents unnecessary water loss through evaporation
  • Saves on pool chemical costs with reduced evaporation
  • Prevents debris from getting into your pool water
  • No installation or ongoing running costs

Cons

  • Requires long exposure to sunlight to heat effectively
  • Need to cut them specifically for freeform pools
  • Not the most effective method for heating (by themselves)
  • Takes up deck or storage space when not in use
  • Can be a hassle putting on and taking off every day
  • Not the most aesthetically pleasing on your pool
  • Needs to be replaced every 2-3 years

4. Solar Rings

Performing the same basic function as a solar blanket are solar rings. These discs are 5 feet in diameter and constructed from a double layer of heavy, UV resistant vinyl. 

The upper layer draws in the heat from the sun, transferring it to the second layer of vinyl and injecting the water with 50% of the heat, warming up the swimming pool.

The rings are also inflatable which allows them to float effortlessly on the surface of the water, while making them easy to store when they aren’t in use. They can float freely or interlock with other rings via magnets. 

The cost for a single ring is around $30, but you can also buy them in packs (ie. 3-packs, 10-packs) which will save you some money due to bulk purchasing.

Pros:

  • Inexpensive solution to heat pool water
  • Inflatable so you can deflate them for easy storage
  • Can be used on any size or type of pool
  • Magnetic for interlocking rings
  • Can use as many as you wish

Cons

  • Circular design means they won’t cover the entire water surface
  • Take a long time to heat up the pool water
  • Can be cumbersome to add and remove every day
  • Resemble lily pads but not very eye-pleasing
  • Will eventually need replacing

5. Wood Stove Heater

Another do-it-yourselfer is a wood stove heater. This one is a bit more in depth when it comes to crafting the heater itself, but if you’re willing to learn or are a natural with DIY projects it shouldn’t be too difficult.

Coiled copper pipe is placed on an elevated rack inside the stove, and the wood fire heats it up. As copper melts at 2000°F, and wood stoves range from 110° to 250°F, you’ll have no issues if you have concerns about the coil melting.

After water has passed through the filter, you split it off into the coil using a diverter valve. The water is then heated as it passes through the coil, and re-enters the circulation system at the return line, sending warm water to the pool.

Crafting the stove will cost about $500 for materials, as you’ll need coiled copper piping (around $300 for 50 ft), a 55 gallon steel barrel, a barrel kit for the legs and door, stove pipe, and connectors to hook it up to your circulation system. You could also use a large wood camp stove that has an elevated rack, although they won’t generate as much heat because the fire isn’t confined.

The nice thing about this method is that the only operational cost is to have a steady supply of wood on hand to feed the fire.

Pros:

  • Can quickly heat water due to the use of fire
  • Relatively cheap upfront costs
  • Only needs wood to operate
  • Rivals gas heater in terms of BTU output
  • More affordable option compared to standalone heaters

Cons

  • Requires advanced DIY knowledge to build
  • Around $500 for materials
  • Aesthetics can look ugly in your backyard
  • Takes up a lot of space
  • Requires a steady supply of wood

6. Solar Panel Heater

Solar panel pool heaters use thermal heat from the sun’s rays to keep your pool warm. 

The panels are usually installed on the roof of your house, although they’re sometimes installed at ground level. Installing on the roof means they’re free of obstructions and shade in order to soak up as much sunlight as possible.

PVC piping is attached to the perimeter of the solar panels. Water gets sent from the filter to the panels, collects heat, and then returns back to the pool through the jets

As with all solar heating methods, the amount of heat generated is dependent on the weather, and how much sunlight the panels are exposed to. Solar pool panels are slow to heat, but once the pool is warmed it’s easy for this heater to maintain that temperature day-to-day.

When sizing your pool for solar panels the rule is to use 50% to 100% in comparison to your pool’s surface area. So, if you have a 16 x 32 pool (512 sq. feet), your solar panels should be between 256 and 512 sq. ft.

The upfront cost of this technology is quite substantial at around $3,000 – $4,000 fully installed, but by tapping into solar energy, you’ll never have to pay any operational costs. 

Pros:

  • Eco-friendly option
  • Uses solar power technology
  • Zero operational costs
  • Good at maintaining pool warmth
  • Pays for itself after about 7 years of use compared to other expensive methods

Cons

  • Expensive upfront cost
  • Solar panels on roof of house can look ugly
  • Need approx. the same surface area of panels as your pool 
  • Slow to heat the pool
  • Dependent on sunlight

7. Heat Pump

Electric heat pumps are one of the most popular ways to heat your pool. Unlike other methods which warm the water using sun or fire, a heat pump uses electricity.

The unit feeds off ambient air from the outside environment. Using a series of compressors and condensers, the air is turned into a gas and further warmed up before being injected into the pool water, and this will only happen if there is sufficient water flow in your circulation system.

Heat pumps are pretty simple to install, but as they require a large amperage you’re best letting a professional do the install job. As long as they are regularly serviced, heat pumps have a long lifespan of about 10 years.

However, one of the main gripes of these pumps is that they’re at the mercy of the outside temperature. Once the weather plummets to 50°F or less, using a heat pump is pointless as there isn’t enough heat present in the air to be harnessed. They also max out at around 150,000 BTUs, which means they take a while to fully heat a pool.

The upfront cost for a heat pump is anywhere from $2,500 to $5,000. Also, with these pumps running on electricity, there will be an increase in your monthly heating costs, but that’s also solely dependent on how often you’re using it. 

Pros:

  • Harnesses heat from outside air temperature for eco-friendly heating
  • Far more energy efficient than gas heaters
  • Up to 150,000 BTUs of output
  • Easy to install as long as there is adequate electrical
  • Works well to maintain heat in pool over time

Cons

  • Expensive upfront cost
  • Requires electricity to run
  • Heating power is capped
  • Slow to medium heat time depending on model
  • Won’t work if outside temperature is under 50°F 

8. Gas Heater

The king of pool heating, the gas heater is the method that will heat up your pool the fastest, and can also heat it to higher temperatures than any other method.

Operating on either natural gas or propane, a fire is created inside the unit. This fire heats up a copper coil which water passes over, picking up heat. 

If you’re running it on natural gas you’ll need to have (or install) a natural gas line. If using propane, you’ll need a tank in the 120 gallon range which can present its own challenges when it comes to refilling.

However, unlike heat pumps, gas allows you to warm the water even in cold temperatures, which makes it an ideal solution to swimming pool heating in the cooler months. 

They also range from 150,000 to 400,000 BTUs of output, which is notable when you consider heat pumps top out at around 150,000. Gas heaters also heat fast for those times when you’ve only a few hours to raise the water temperature.

Ranging between $1,600 and $3,000, gas heaters aren’t going to break the bank, but the cost of fuel will be where you’ll notice a sizable dent in your wallet, especially if you live in an area where gas is expensive.

Pros:

  • Fast-heating option
  • High-heat output at 400,000 BTUs
  • Can use with either natural gas or propane
  • Reasonable upfront cost

Cons

  • Requires installation of gas line or propane tank
  • Propane tanks are large and a pain to refill
  • Use of gas is expensive
  • Not environmentally friendly

9. Windproof Enclosure

Wind has a highly detrimental effect when it comes to pool water, as heat escapes through the surface of the pool. When the wind picks up, heat loss is exacerbated.

A way around this is to cut down the amount of wind that gets to the pool by creating an enclosure. Similar to transforming your outdoor pool to an indoor pool, an enclosure can allow you to swim year round, no matter the weather.

Pool enclosures can look like a dome or solarium. Depending on the model, they can be low, medium, or high profile, and some will even fully retract, so you can block wind from one end of the pool while still swimming outdoors.

Enclosures aren’t cheap though. There’s a wide range of them due to the materials they can be built from, the various sizes they come in, and if they’re static or retractable. On average, you can expect to pay around $10,000 for a quality enclosure.

Pros:

  • Removes wind from the surface of the pool
  • Cut down on heat loss by trapping warmth in the enclosure
  • Available in retractable models for custom use
  • Visually unique
  • Keep dirt and debris from entering the pool water
  • Saves on sanitizing chemicals
  • Allows for year-round swimming

Cons

  • Most expensive option
  • Needs prolonged sunlight exposure to slowly raise water temperature
  • If water becomes dirty, chloramine smell can get trapped in enclosure
  • Some enclosures require professional installation

It’s Getting Heated!

Heating your swimming pool is a luxury you can now afford.

With multiple options available, you can go the route of a standalone heating unit, solar covers, or DIY, all off which will keep you pool water at a more comfortable temperature to swim in.

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