Hayward HeatPro HP21104T Review

The HP21104T is part of the Hayward HeatPro line of electric heat pumps designed for inground pools.

Top Ten Reviews Verdict

The Hayward HeatPro electric heat pump is a high-efficiency inground pool heater that can maintain your pool’s ideal temperature for longer swimming seasons.


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    The HeatPro costs less to operate than gas heaters.


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    It requires warmer ambient temperatures to heat your pool and run efficiently.

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The HP21104T is part of the Hayward HeatPro line of electric heat pumps designed for inground pools. It’s quiet and energy efficient, which makes it a great way to heat your pool and maintain its temperature. Because heat pumps use the surrounding air to heat the pool water, the HeatPro is best suited to locations where the temperature rarely dips below 50 degrees Fahrenheit. Depending on where you live, it can extend the summer swim season for about a month on either end. As with all heaters, we recommend also using a solar cover when the pool is not in use to insulate the water to prevent heat loss and evaporation.

The Hayward HeatPro line of heat pumps has several size options that range from 95,000 British thermal units (Btu) to 140,000 Btu. We examined the HP21104T, which has an output of 110,000 Btu. We chose this model because it has the capacity to heat our hypothetical 15,000-gallon pool with about 500 square feet of surface area. However, most product lines, including the HeatPro line, have very similar features across different size models. So, if you need more or less power than 110,000 Btu, check out Hayward’s other HeatPro sizes.

A heat pump’s efficiency is rated as a coefficient of performance (COP). This is a number higher than one determined by each manufacturer, and it changes depending on different circumstances. This means the COP isn’t the most reliable metric, but it does give you some idea of the product’s efficiency. Hayward is helpful in that it gives the HeatPro’s COP under different circumstances. For example, the HP21104T has a COP of 5.7 when the ambient temperature is 80 degrees Fahrenheit with 80-percent relative humidity and you set 80 degrees as your desired water temperature. The COP goes down (higher is better) as the ambient temperature drops.

Because heat pumps rely on the heat in the outside air, most products do not work in temperatures below 50 degrees Fahrenheit. The HeatPro, however, is available in a low ambient option that works until temps hit 40 degrees. We like that this option allows a little more flexibility and keeps you swimming longer.

Though heat pumps tend to cost more upfront than gas pool heaters, like the Hayward Universal H200 or Pentair MasterTemp, they cost less to operate and also tend to last longer. The HeatPro is built with a rugged UV-resistant, weatherproof exterior to protect against environmental damage. It also features an Ultra Gold evaporator fin that resists corrosion, even in coastal environments, and a titanium heat exchanger that also resists corrosion. These are important because corrosion is a leading cause of pool heater and heat pump failure.

The HeatPro features a control panel with a digital display. This allows you to set and lock temperature preferences and monitor when the heat pump is on and heating. The screen also displays fault messages when the heat pump’s self-diagnostics find something amiss with operations.

Hayward offers a one-year warranty on the HP21104T and all its HeatPro products. We advise having a professional install your heat pump, as improper installation may void the warranty and cause problems with your heat pump’s operations. You can reach Hayward’s customer service by phone, email or snail mail.

Overall, the Hayward HeatPro electric heat pump is the best way to heat your pool if you swim a lot when the weather is warm. Its low operational costs and high efficiency let you keep your pool at your ideal temperature without worrying about your budget or the environment.

Rebecca Armstrong

Rebecca has been writing about technology since 2015. She specializes in smartphones, phone plans, DNA tests and home networking equipment. She has a bachelors degree in creative writing and English literature from the University of Evansville. Rebecca currently works as the co-founder of All Times Are Local, a foster care organization.