High Performance, highly reliable and in a compact package. The AstralPool HiNRG Heaters are designed for rapid heat up of your swimming pool or spa and to work with today’s energy efficient variable speed pumps, even when set on energy efficient low speed. Available in three models, the 175, 250 and 400, the HiNRG Heater can be ordered for Natural Gas or LPG and has kilowatt equivalent outputs of 39 kW, 55kW or a massive 90 kW. The build quality, an important factor for gas pool and spa heating is so high that the HiNRG Heater is covered by a 5 year limited warranty on both commercial and residential installations.