How pool heaters work varies between gas, electric, and heat pump systems. Gas and electric heaters will generate energy to heat a coil that warms up your pool’s water. The water cycles between the pool and the heater, ensuring it always stays at the right temperature.
Heat pumps are different — they use a fan that extracts the warm air from the outside and passes it over an evaporator coil. The refrigerant mixes with the warm air to create a gas, which travels to a compressor. Once the system deems everything hot enough, the water pumps back into the pool at the perfect temperature.