When it comes to heating your pool, traditional systems often come along with high energy costs and more wear and tear. So, you should consider TherMax Extreme Solar Pool Heater – well-known for efficiency, affordability, and durability. This solar pool heater features a closed-loop system. Generally, pool heaters come with an open-loop system and their pool pumps push water against gravity while causing wear and increasing operational costs. But TherMax Solar Pool Heater differentiates the heating fluid and pool water using a heat exchanger, circulating a small amount of water or glycol through solar evacuated tubes.