What is Solar Pool Heat?

A solar pool heating system uses the heat from the sun to heat your swimming pool using flat panels that are attached to your roof. The heat exchangers are a flexible polymer flat black panel.

The number of panels required is determined by the:

  • Size Of The Pool 
  • Direction And Space Of Available Roof
  • Desired Pool Temperature.

Need More Information About Solar Pool Heat?  
Contact Fafco Solar or Call 239-574-1500.

Why Should I Consider Solar Pool Heating?

Even in Florida, standing water can be quite cold. When the sun is shining and it is warm enough to swim, it is common for the pool temperature to be too cold to be comfortable.

Solar pool heat can be used all year long to heat your pool using just the sun! Why pay for electricity or propane/gas to achieve water temperatures that can be reached free from the sun?

Need More Information About Solar Pool Heating? 
Contact Fafco Solar or Call 239-574-1500.

Can I Use Solar Pool Heat And An Electric Or A Gas Heater?

Solar pool heat can be used in conjunction with any auxiliary heater. On very cold days, an additional heater can quickly reach the desired temperature.

Typically, a solar pool heating system is adequate for reaching the needed temperature year round in our exceptional climate.  However, if the pool is being used for guests or the home owners are only in town for a brief time and they want to utilize the pool in colder weather, an auxiliary heater can be useful.

The solar is still more economically beneficial. It will raise the temperature well above what it would be without any solar pool heat causing the additional heater to use less energy.

Need More Information About A Solar Pool Pump?  
Contact Fafco Solar or Call 239-574-1500.


Will I Need A Different Pool Pump?

Newer pool pumps (newer than 10 years) are normally adequate to circulate the water thru the panels. However, if a home is a high 2‐3 story or has numerous water features, a larger pump may be required.

Need More Information About A Pool Pump?
Contact Fafco Solar or Call 239-574-1500.

Can You Use Pool Solar Panels To Tie Into Water Heat For The House?

The solar collectors used to heat the pool are not rated for potable or drinkable water, so they cannot be used for both.  A domestic solar water heater must be installed independently from the pool heater.

Need More Information About Pool Solar Panels?
Contact Fafco Solar or Call 239-574-1500.

How Many Solar Pool Panels Do I Need?

There are many variables that attribute to the required number of panels needed to heat your pool.  The largest variable is expectation.

Ideally, we would measure the surface square footage of your swimming pool and install anywhere between 80%‐100% of the pool square footage in solar panels on your roof. The roof space available and what direction the panels must be oriented can also affect the number of panels desired.

Need More Information About Solar Pool Panels? 
Contact Fafco Solar or Call 239-574-1500.

Does The Solar Pool Panel Have To Go On The Roof?

A solar pool heater is most effective on the roof. However, if the land space facing south is available the collectors can be mounted on a fixed wood or aluminum rack.

Need More Information About A Solar Pool Panel?  
Contact Fafco Solar or Call 239-574-1500.

How Warm Can A Solar Pool Heating System Get My Pool?

Most of the year in our region, you can get your pool just about as warm as you would like it.  However, between January and March, we can experience cool days and some colder nights, causing our pool water temperatures to decrease. 

At this point the solar pool heating system will raise your pool temperatures between 10‐15 degrees above the Gulf of Mexico (or any significant standing body of water).  A chart of anticipated temperatures in the various times of the year is available.

Need More Information About A Solar Pool Heating System?
Contact Fafco Solar or Call 239-574-1500.

How Are The Solar Collectors Attached To The Roof?

A system of stainless steel fasteners, tie down brackets, Eagle Claws, and Dacron straps are used to attach the collectors to the roof. The method varies with the type of roof.  A special sealant is used to assure no leaks.  This system of attachment exceeds the Miami‐Dade wind load codes.

Need More Information About Solar Collectors. 
Contact Fafco Solar or Call 239-574-1500.

Can The Roof Solar Collectors Be Installed On A Metal Or Tile Roof?

All of our solar items can be installed on either a tile or metal roof of all kinds. Our 40 plus years of experience has given us the expertise to provide a water tight seal.

Need More Information About Roof Solar Collectors?
Contact Fafco Solar or Call 239-574-1500.

Can Solar Pool Panels Be Installed Horizontally Instead Of Vertically?

Due to the required draining and flow of water, the solar collectors must be in the vertical position to allow for appropriate plumbing.

Need More Information About Solar Collector Installation?
Contact Fafco Solar or Call 239-574-1500.

For Solar Collector Efficiency What Direction Should They Be Installed On The Roof?

The southern roof is ideal for maximum winter heat. The second choice would be the West. East and North can be much less effective in the winter when the heater is used the most. 

A chart explaining efficiency loss is available.  If the panels need to be installed in a less than ideal position, it can be compensated for with additional panels.

Need More Information About Solar Collector Efficiency?
Contact Fafco Solar or Call 239-574-1500.

Should I Buy The Cheapest Solar Pool Heating System I Can Find?

Like most products, you get what you pay for. Solar pool heating systems are expected to perform for many years, so selecting the right product and installer is critical. Selecting a cheap solar pool heater will not provide the best value. Price is only one factor when deciding to use solar energy to heat your pool. Other important factors include:

  • Performance of the solar collector. Fafco manufacturers industry leading solar panels with the highest BTU/area ratings. The Fafco Revolution panel boasts a 1,063 BTU/sq. ft. rating from the Florida Solar Energy Center. The more thermal energy a panel produces, the warmer your pool will be and the faster solar panels will heat your water.
  • Experience of the installer. Fafco Solar, a family owned business, has been installing solar pool heating systems in Southwest Florida for over 35 years. Fafco, Inc. is the oldest and largest manufacturer of solar pool heating panels in the United States. No competitor can match our experience with solar pool heating. To ensure a trouble free installation, select a company that you can trust.
  • Options. We are proud to offer two different types of solar pool heating systems with varying performance ratings, sizes and designs. Sunsaver ST separated tube design and our high-performance Sunsaver panels. Don't settle for just one option!
  • Service after the sale. We are there for you! Fafco Solar will be there to provide you with excellent customer service. Many customers return to us years or even decades later for other solar energy products after enjoying the savings and benefits of solar pool heating.

"Cheap" solar pool heaters are not in our vocabulary. Our prices are very competitive, but we focus on quality and service. Call 239-574-1500 and let us show you what Fafco Solar can do to earn your business!

Can I Install My Own Solar Pool Heater?

We will provide all of the materials and directions required for a DIY installation.  However, the savings is minimal by eliminating the installer’s labor costs, and the 12-year warranty can be voided if the installation is not precise.

Need More Information About A Solar Pool Heater Installation? 
Contact Fafco Solar or Call 239-574-1500.

Will My Existing Pool Pump Work With Solar Pool Heat?


In most cases, your existing pool circulation pump will work fine with solar pool heat. All solar pool heat systems add back pressure to your circulation pump. Most of the increased pressure is from lifting the water to your roof and the pipe and fittings to carry the water to your solar panels. The solar panels themselves only add 2-4 PSI of pressure to the system.

Fafco Solar will evaluate your pump to ensure that is it adequately sized for solar pool heating.

Some competitors claim that our solar panels create excess back pressure on your pump. By design, Fafco panels use a unique subheader (FAFCO Patent 6038768) that makes for a rigid connection between the header and the collector surface - this is where many other brands fail. This subheader adds just 1-2 PSI of pressure. The difference is more than made up because our competitors' systems require a substantial length of extra pipe for the return line. Fafco's unique manifold system allows the feed and return line to be as close as possible to the pump.

For an independent technical explanation of solar pool heat systems, including pressure calculations, see Florida Solar Energy Center's Solar Swimming Pool Heating Systems documentation.


What Is The Solar Panel Warranty?

Effective January 1, 2014, Fafco Solar offers solar pool heating collectors with a 12-Year Limited Warranty and Limited Lifetime Replacement Warranty supplied by the manufacturer, FAFCO, Inc. of Chico, CA. 

Revolution and Sunsaver Solar Pool Heating Collectors installed prior to January 1, 2014 may have differing warranty terms. See your warranty statement for full details.

Need More Information About The Solar Panel Warranty? 
Contact Fafco Solar or Call 239-574-1500.

How Do I Protect My Solar Pool Heater From Freeze Damage?

Panels may be damaged by freezing when not fully drained.

Protecting your system against freeze damage is important, even in Southwest Florida where we do not experience many freeze events. The best, and only manufacturer approved way to protect FAFCO solar pool heating panels from freeze damage is to completely drain water from panels when temperatures approach freezing. Fafco Solar recommends that Southwest Florida homeowners completely drain solar pool heating panels if temperatures are expected to be below 45°F. Most systems are 100% self-draining, and no action is required except shutting off the system during freeze events.

The types of installations which are most prone to freeze damage are systems that have panels below the pool water level, or systems which have a piping configuration which does not allow for gravity drainage of the water. Some systems that are piped in a manner that does not allow automatic draining are equipped with a manual drain valve. This valve, if present, must be fully opened during freezing conditions. If you wish to operate your circulation pump and filter during freezing conditions, the solar pool heating system should be isolated by closing the isolation valves and bypassing the solar collector loop.

If panels are mounted flat on a roof (or less than 10 degrees of pitch), the manufacturer recommends that the panels are drained by removing the vacuum relief valve and end cap and lifting the panels to fully drain water from the system. Because this procedure involves getting on the roof, you may wish to have Fafco Solar do this work for you, but do not wait until freezing temperatures are imminent!

Note that operating your solar pool heating system during freezing conditions is not an acceptable freeze protection method per the FAFCO manufacturer's warranty.

Panels installed in accordance with the FAFCO installation manual are covered by warranty against freeze damage, but only when the system owner maintains the system consistent with the operator's manual. Proper maintenance includes ensuring that panels are fully drained during freezing conditions. If you have any questions, please contact Fafco Solar before freezing conditions are expected!

Call Us: (239) 574-1500

How Do I Maximize My Solar Pool Heater's Performance?

Solar pool heating systems are relatively simple in terms of how they work, and will operate trouble-free for many years in most circumstances with minimal maintenance. There are some things you can do to maximize your solar pool heating system’s performance, however.  

  • Use a pool cover, also known as a pool blanket or solar cover. 
  • Install an automated electronic solar controller. 
  • Keep your filter clean. 
  • Install a variable speed pump. 

Pool Covers   

Solar blankets keep heat and water in your pool. Pool covers are the single most effective way to improve the performance of your solar pool heating system. If you heat your pool with electricity or gas, you lose heat (money) overnight or when the pool is not in use. With solar pool heating, uncovered pools will have a lower starting temperature each day, resulting in lower maximum temperatures possible with solar heating throughout the day. If your pool starts off already-warm from the day before, the solar pool heat can work more effectively.  

It’s easy to lose 5 degrees of temperature overnight on an uncovered pool, and this effect is pronounced when night temperatures are low and as wind increases. One misconception is that the pool cover heats the pool substantially. While solar blankets can provide some heat gain to a pool, the most important effect is that it reduces evaporation. Evaporation releases heat from your pool. Refilling lost water is wasteful and puts more cold water in the pool!

Automated Controllers   

Automated controllers like the Pentair SunTouch maximize solar pool heating performance. Automated electronic controllers are used to “switch” your solar pool heater on and off based on some preset criteria. You can set a maximum temperature for your pool or spa, and the controller will turn the solar off when the set point is reached. More importantly, the controller will turn off your solar pool heater when the solar panels are unable to make your pool warmer. In fact, solar panels can cool your pool under a variety of conditions likely cloudiness, rain, shade, dusk, and dawn.  

Manually operated solar pool heaters rely on the owner to turn valves into the proper position manually, and it’s obviously impossible to constantly monitor and adjust the valves to maximize the solar panel performance. Manual systems rely on the existing circulation pump to operate only when the system is most likely to have solar energy available, but a simple timer can’t detect the weather! That’s where the controller comes in. The roof and pool temperatures are constantly monitored and compared, and a motorized valve switches the solar pool heater on and off as necessary, turning the system on when solar energy is available and needed, and off when there is no solar energy available to heat the pool.  

Sometimes pools have existing automation products. Various pool control systems from Jandy, Pentair, Hayward, and others are compatible with solar pool heating systems, and can easily be set up to control valves automatically. If your pool does not have an automation system, we can add one that does whole-system control, or just controls the solar aspect of your pool operation. Most controllers also have the capability of controlling variable speed pumps (see more on variable speed pumps below).  

Clean Your Filter   

Keeping your pool cartridge filter clean will improve solar pool heating performance. Actually, clean or replace your filter on a regular schedule. Clogged filters result in lower flow rates due to increased pressure on the outlet of the pump. Dirty filter cartridges can prevent solar panels from filling evenly and fully, and result in lower flow rates, which means less overall heat transfer to the pool. They also contribute to a common phenomenon called “bubbles in the pool.” We get this call very frequently, and it’s easily confirmed as a dirty filter by running the pool pump with the cartridge removed and comparing the system pressure or flow rate.  

Sometimes a filter that appears to be clean is actually heavily impacted with small debris. Your filter cartridge should be quite light, even when wet. If your filter feels heavy, you’ve probably got a clogged filter, and it may not be possible to clean it sufficiently. If this is the case, then it’s time to replace your cartridge. The lifespan of a cartridge depends on many factors like size and how dirty your pool gets. A filter can also become clogged from pressure washing pool decks or chemical treatments that precipitate solids which end up getting picked up by a vacuum.  

Variable Speed Pumps   

Variable speed pumps like the Pentair Intelliflo help optimize solar pool heating performance. They are the hot new technology in the industry.  These pumps use variable frequency drives and brushless motors to significantly reduce pool circulation and filtration costs. A positive side effect of the variable nature of the pump speed is that we can control how much water goes through the solar pool heating system, optimizing performance.

Manufacturer recommendations vary, but typical solar pool heating panels require about 4 gallons per minute per collector to reach optimum performance. Any additional flow results in marginal pool heating performance gains at substantial and unjustified costs to pump extra water. By installing a variable speed pump with a flow meter, we can “dial in” an optimum pump speed that balances the need for solar pool heating performance with pump operation costs.  

As a side note, many people assume that a low flow rate is better, allowing the water to spend more time in the solar panels getting warm. However, solar panels perform better (transfer more heat to the water) when operating at a lower temperature. Letting water stagnate in a solar panel just heats up the panel, reducing efficiency. The water coming out of you pool jets should be just a little bit warmer than the rest of the water in the pool. Relatively high volume with low, steady temperature rise is ideal.


How Do I Turn Off And Isolate My Solar Pool Heating System?

Pool plumbing can be confusing. Solar pool heating valves can add to that confusion. If you want to learn how to turn off and isolate your solar pool heating system with manual valves, you’ve come to the right place. The images and videos below show you how to turn the valves correctly to change the flow of water in your system.

To prevent pump damage, you must bypass the solar loop before isolating the system for service or repair. This article focuses on high-quality two-way and three-way valves installed by Fafco Solar. It applies to valves made by Pentair, Praher, Jandy, and Hayward – all work basically the same way. Note that this does not apply to basic red, gray, or blue handled ball valves, which are far inferior to the valves shown. Ball valves have different handle orientations, so this article should not be followed for those systems.

For more information on how these valves work, here is another video.

Note that the OFF tab on the valve handle always points to the pipe that is blocked. Your system may or may not have labels, but the important thing to remember is that the OFF tab is where the gate that stops water flow is located. 


Your valve configuration may be different, on the ground rather than the wall, or may not contain all of the pictured valves. If you have any questions about how to turn off and isolate your solar pool heating system, call Fafco Solar at (239) 574-1500.

Bubbles In The Pool With Solar Pool Heating?

Dirty Pool Filters Cause Bubbles in Pool With Solar Pool Heating

One of the most common questions about solar pool heaters is why bubbles are sometimes seen in the pool. Air enters the pool circulation system and comes out of the jets into the pool. Why does this happen?

First, it's important to understand whether the air is coming from the solar pool heating system or elsewhere in the pool circulation system. Bypassing the solar panels (turning solar pool heating off) can help determine if the source is the solar pool heater. If bubbles go away with the system off, it is likely that air is entering the vacuum relief valve on the roof. Air enters this valve when there is not enough water flow in the system to close the valve. This can happen for a variety of reasons, including:

  • Your filter may be dirty. Even if you have recently cleaned your filter, fine particles may have accumulated, indicating it's time to replace the cartridge altogether. A filter that "looks" clean is not necessarily clean. You can check to see if a dirty cartridge is the culprit by running your pump with the cartridge removed and the filter housing reassembled. If the filter is too dirty, the bubbles will have stopped and the pressure gauge will have a substantially lower reading.
  • Running a suction cleaner can reduce the output pressure of the pump.
  • The pump is faulty or failing.
  • There is an obstruction in the suction or return plumbing that is causing the total system pressure (total dynamic head in technical terms) to be increased. Checking total dynamic head requires the use of vacuum and pressure valves on the pump and is best left to the pros.

If the solar pool heater is not the source of the air bubbles, you likely have a suction leak somewhere else in the plumbing. You can check the following:

  • Check the level of the water in your pool. Low water levels can allow the skimmer to suck air into the system.
  • A whirlpool effect in your skimmer basket may be drawing air into the system. This is more likely if the pool level is low.
  • Run a gentle stream of water from a hose over suction plumbing fittings and valves and see if the bubbles stop. You should see the bubbles reduced in the pump's filter basket.
  • The filter basket cover may be loose or the o-ring may be deteriorated. Again, running a gentle stream of water over the pump housing may reveal this.
  • Check that the bolts are tight between the pump housing and the pump motor. Air may enter the system at this junction. Again, running a gentle stream of water over the pump housing may reveal this.
  • Suction leaks can exist in plumbing that is not exposed (underground). Hiring a leak detection specialist may be required.

If these diagnostic steps do not solve the problem with bubbles in your pool with solar pool heating, call Fafco Solar at (239) 574-1500 and we will be happy to assist you.

How Do I Put My SunTouch Solar Pool Heating Controller in Service Mode?


If you have a Pentair SunTouch solar pool heating controller and need to shut off your pool pump to clean your filter, add chlorine tablets, or perform other service on your pool, you can use the Service Mode to shut off all pumps and be assured that pumps will remain off while you service your system. Check out this video to learn how!


How Do I Adjust The Clock On My Pentair SunTouch Solar Pool Heating Controller?

To adjust the clock on your Pentair SunTouch solar pool heating controller:

  1. Press Menu 5 times until Main Menu 5/14 Clock is shown on the screen
  2. Press the right arrow.
  3. Change the hour with the up/down arrows. 
  4. Press the right arrow.
  5. Change the minutes with the up/down arrows.
  6. Press the right arrow.
  7. Press the left arrow to return to the main status screen.

How Do I Get My Solar Pool Heater Ready For Summer?

With so many people in Southwest Florida preparing to head north for the summer, Fafco Solar is getting lots of calls from people with solar panels. How do you get your solar pool heater ready for summer?  

If you are not planning to use your solar pool heater in the summer, the most important thing you can do to protect your system is to drain and isolate it completely. Most of the systems Fafco Solar has installed, and all of the systems we have installed in recent years, have isolation valves that allow you to stop the flow of water into and out of the solar panels and roof plumbing. Just closing the 3-way solar bypass valve is not enough. There are two ways that water can continue to rise to the roof when the bypass valve is closed (through the return line if there is no check valve present and through a small hole in the 3-way valve that is present for daily draining purposes).

If you do not drain your system completely, water can stagnate in the panels and plumbing causing excessive temperatures. While usually not a problem, occasionally this leads to severely warped or swollen PVC pipe on the roof. Black pipe exhibits this problem more than white pipe, but extreme temperatures can also cause white pipe to discolor and warp. This phenomenon may be more pronounced in Southwest Florida due to our long, hot summers and numerous part-time residents. Roof plumbing issues due to improper operation of your system is not covered under warranty.  

Your system is likely plumbed to drain automatically when the pool pump is turned off, or a manual drain may be installed. To isolate your system, first turn your pump off, let the system drain completely for a couple of hours (or drain panels manually if necessary). If you are able, opening the lower header end cap on the roof is a fail-safe way to make sure your panels are completely empty. Once the system is completely drained, close your isolation valves. Please keep reading, especially if you have automated valves!  

It is critical that the 3-way solar bypass valve remains in the solar-off (bypass) position. If the 3-way valve is turned to the solar-on position and the isolation valves are closed, your pump will “dead head,” possibly causing catastrophic failure of your plumbing or pump.  

If you have an automated controller, there are multiple ways to turn your solar pool heater off, but generally speaking you can turn the desired temperature down as far as it can go. Some controllers have manual off switches. The motorized actuator on the 3-way solar bypass valve has a switch that can be used to stop the valve from turning. Unless you are very comfortable with your automation system and/or pool valves, it is not recommended that you attempt to isolate your solar pool heater for the summer without professional assistance. For a nominal charge, Fafco Solar can come out to fully drain and isolate your system and return after summer to start, test, and optimize your system.