Best Tankless Pool Heaters – Reviews and What You Need To Know

Last Updated on October 19, 2021

When it comes to the ultimate relaxation, there’s nothing like jumping into a comfortably warm pool after a long day. And as a pool owner, we believe that one of the best ways to achieve this ideal setting is with the help of tankless pool heaters.

What is a Tankless Water Heater?

Tankless water heaters are currently in-demand for homes looking to become more energy-efficient. Unlike traditional water heaters that need to continuously heat and reheat water, tankless water heaters produce warm water using powerful gas burners or electric coils so it does it faster.

It does use more power, however, without the need to reheat the water, tankless water heaters becomes the more energy-efficient option and is the main reason why it became popular to various households.

Now, the question you might be asking now is if you can use standard tankless water heaters on your swimming pool to keep your pool water warm.

Can I Use Standard Tankless Water Heater On My Swimming Pool?

Well, you can do so, but that might not be the best way to heat your pool since domestic tankless water heaters were not designed for that purpose.

This setup will require you to run two different pool pumps at the same time since the typical pool pump may overwhelm your tankless water heater and it may not be able to properly heat the water that will pass through it.

If you plan to use a separate domestic tankless water heater, you have to get a pool pump that has a low flow rate that will be just right for your heater.

Tankless water heaters sold for residential use were designed to produce a relatively large water temperature gain at a relatively low flow rate. A swimming pool requires a relatively small water temperature gain on a relatively large flow rate.

Since getting a tankless water heater is a good indication that you plan to save money on energy costs, the best alternative we could think of is by buying a tankless water heater designed for pool heating.

A reliable tankless electric pool heater can be the best solution to keep your swimming pool comfortable and energy-efficient for years.

How Do Tankless Water Heater For Pools Works?

Tankless water heater for pools works the same as a residential hot water tankless heater would — they operate based on demand.

On-demand pool heating works when cold water from your pool enters and the sensors inside the heater ignites the burners or its heating elements. Once the water temperature reaches your desired temperature, the warm water will exit the heater and go back to your swimming pool.

The tankless pool heater should be installed on your existing pool circulation system so that the heater will be right after the water passes through your pool filter. This way you’ll have debris-free water entering your electric pool heater.

Best Tankless Pool Heater: EcoSmart Smart Pool 18 Electric Tankless Pool Heater

EcoSmart SMART POOL 27 Electric Tankless Pool Heater, 27kW, 240 Volt, 112.5 Amps with Self Modulating Technology
  • Flow Activation
  • Eco smart Pool Heaters are compact and easy to install for a new or existing pool
  • Set your temperature digitally to increments of 1-Degree. Set it and forget it.
  • Compatible with Eco smart Remote Control. Activation Flow - 12 +/- 2 GPM

When we were choosing a tankless water heater for pools, we really liked the Smart Pool series by EcoSmart. They offer fast and efficient heating of swimming pools up to 15,000 gallons, especially the EcoSmart Smart Pool 18 Electric Tankless Pool Heater.

EcoSmart Pool Heaters works by utilizing the latest flow sensor technology instead of the traditional pressure switch activation, this increases its overall functionality and reliability.

The manufacturer states that this tankless water heater for pools can raise the water temperature by 10 degrees in a 15,000-gallon swimming pool in about 13 to 15 hours. Also, the Smart Pool Series are known to be energy efficient no matter what the ambient temperature is in your pool area.

If you’re decided on getting an electric pool heater, you must be aware of the required voltage to properly and safely install this product. The Smart Pool heater needs to get its power from a 200 amp electrical panel and it must be connected to two or three 50 amp breakers (varies depending on the Smart Pool model that you’ll be using).

Pool owners who bought the Smart Pool electric pool heater love how small and silent the unit can be. This pool heater is very compact and is very easy to use even for a first-time pool owner. It also has a built-in digital thermostat control that allows you to set your desired temperatures for your pool.

For those with smaller pools, we recommend going with the EcoSmart Smart Pool 18 Electric Tankless Pool Heater to further save on your energy bill and get the best pool heating experience.

EcoSmart SMART POOL 18 Electric Tankless Pool Heater, 18kW, 240 Volt, 75 Amps with Self Modulating Technology
  • Flow Activation
  • Ecosmart Pool Heaters are compact and easy to install for a new or existing pool
  • Set your temperature digitally to increments of 1-Degree. Set it and forget it.Required Wire:2 x 8 AWG
  • Compatible with Ecosmart Remote Control

Benefits Of Using Tankless Pool Water Heaters

Easy Installation

Maybe you’re already aware of how difficult it can be to install a gas-powered pool heater or solar-powered pool heater, whether you’ve heard a fellow pool owner complaining about it or you’ve experienced it yourself. This is one of the main reasons why tankless pool heaters are a popular choice for those who want to install a usable pool heater fast and easy.

You can skip the hassle of installing and using a propane or natural gas source just to heat your swimming pool. Another great thing about tankless pool heaters is their space-saving design, this makes them a good option for various pool sizes from small to large ones.

High-Efficiency Rate

A report from the DOE’s Brookhaven National Laboratory in New York found that the average swimming pool heater (pool heat pumps and gas pool heaters) has an efficiency rate between 80 and 85 percent. If you’re not familiar with how that reflects in real life, let’s say you put $100 of fuel into the heater, your device then creates $80 to $85 of heat, and the rest of it is lost or wasted.

On the other hand, tankless pool water heaters can reach up to 99.8 percent efficiency, regardless of the type of pool it is used on or your surrounding’s ambient temperature, both can affect the efficiency of pool heat pumps, solar pool heaters, and gas-powered pool heaters.

Low Maintenance

Unlike traditional gas-powered pool heaters, tankless water heaters don’t require much maintenance. For pool owners residing in places with hard water, a vinegar flush every 500 hours can help prevent mineral buildup or scaling to occur. This 15-minute task can be done by either a professional or you, the pool owner.


When it comes to reliability, the best pool heater you can get is an electric water heater. While gas heaters may not work properly at extreme temperatures and pool heaters using solar panels heavily rely on the sun, electric tankless pool heaters can still run even if those factors are present or not.

You can use these electric pool heaters any time of the year to heat your swimming pool.

Frequently Asked Questions About Pool Heaters

How long do tankless water heaters last?

Gas-powered tankless heaters typically last for 20 years or more, this is two or three times longer than traditional tank-type heaters. Meanwhile, electric tankless heaters can work for 7 to 10 years.

What’s the best pool heater on the market?

Depending on your needs and preferences, you can either go with an electric tankless pool heater for less energy cost or choose a gas-powered pool heater to heat your pool water fast.

You can check out our post about the best pool heaters today to help you decide.

How often should I run my pool heater?

If your swimming pool is not going to be used for several days or weeks, it is recommended that you let it cool down and only run your heater the day before you want to use it again.

It usually takes about 24 hours to raise a pool to your ideal temperature, but this estimate varies depending on your location and your pool’s starting temperature.

A pool with a water temperature of 78 degrees Fahrenheit or higher can already be considered warm and comfortable to use.

If you are trying to lessen your energy costs, you can run your heater only when the temperature in your swimming pool dips below 78 ℉.

Read more about the best pool temperature for swimming to determine what’s the ideal temperature to set your pool heater on.

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