SmartPool SunHeater S120U review

Extend your swimming season the eco-friendly way with the SmartPool SunHeater S120U Universal Solar Pool Heater.

SmartPool SunHeater S120U review
(Image: © SunHeater)

Top Ten Reviews Verdict

Easy to install and cost-effective, this eco-friendly solar pool heater will add weeks to your swimming season without breaking the bank. It’s suitable for both in-ground and and above-ground pools, and uses heat from the sun’s rays to raise the temperature of the water in your pool.


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    Easy to install

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    Uses existing pool pump

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    No fuel bills


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    Requires long hours of sunlight

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Here's everything you need to know about the SmartPool SunHeater S120U Universal Solar Pool Heater.

Below you'll find all the pros, cons, and everything else to consider for this model. Find out how it fared against its competitors in our best pool heaters guide. 

SmartPool SunHeater S120U: What you need to know

If you’re looking for an inexpensive, eco-friendly way to heat your pool, you’ve found it. This solar pool heater raises the temperature of the water in your pool using heat from the sun’s rays. It works in conjunction with your pool pump, which pumps water through the solar collectors. The water gets heated by the sun as it shines on the collectors before it returns to your pool.

SmartPool SunHeater S120U: Price

There’s no escaping the fact that solar pool heaters can be expensive in terms of initial outlay, but the beauty of this type of heater is the fact that you'll have no additional fuel bills. We think this is excellent value for money, particularly as you shouldn’t need to buy a new pool pump if you already own one.

SmartPool SunHeater S120U: Design & features

Using solar power to heat your pool is the most eco-friendly option. It’s cost effective too, as you won’t have any additional fuel costs relating to heating your pool. You will, of course, need plenty of sunshine! This solar pool heater is designed to be used with your existing pool pump, and you’ll need at least six hours of sunlight during the day. The longer the solar collectors are in full sunlight, the better they’ll work and the warmer your pool will be. This particular solar pool pump will raise the temperature of your pool up to 10 farenheit / 6 Centigrade during swimming season. It won’t work as well when the weather is cloudy or rainy, but your water will be back up to temperature after one or two sunny days. 

SmartPool SunHeater S120U: Performance

In 68 ratings, Amazon reviewers have given this solar pool heater 3.1 out of 5 stars. Reviewers pointed out that this type of pool heater won’t keep your pool at a consistent temperature, but it’s more than up to the task if you have plenty of hours of sunlight.

SmartPool SunHeater S120U: User reviews

Best Reviews Guide ranked it first place in a review of the best solar pool heaters in November 2019. Lintons in the Garden found installing this “very easy” and “a source of joy for those who love DIY projects”. They say it’s much simpler to operate than gas or electric pool heaters as it doesn’t have any “fancy led control panel for temperature control or a digital interface” but it does “bring up pool temperature a few degrees higher in the most cost-effective manner”.

Positive reports continue at Magesolar who found this to be the best value solar pool heater you can buy. They say it has “excellent efficiency ratings, a staggering lifespan, and an admirable ability to reduce carbon emissions” as well as the capacity to reduce a homeowner’s pool heating costs by up to 70%. They also say it'll pay for itself over the course of its lifespan.

Should you buy the SmartPool SunHeater S120U?

Yes, if you’re looking for an eco-friendly way to heat your pool and you live in a climate that has at least six hours of sunshine. It’s good value for money and a practical choice if you have an existing pool pump and would like to enjoy swimming in a heated pool without additional fuel costs.

For a more powerful alternative, have a look at our Hayward H-Series H250FDN review or the EcoSmart Smart Pool 18 review. For other energy-efficient options, head over to the best solar pool covers guide.  

Heidi Scrimgeour

Heidi has written for an assortment of high profile publications, including Grazia, Red, and Mother & Baby magazine. She has a Masters degree from the University of Westminster, and works as a freelancer writer and copy editor.