- Description The AstralPool JX gas pool and spa heater is a premium fan forced heater designed for wall mounting. Available for indoor and outdoor application and ideal for confined spaces. Forced draft combustion system means lower clearances from windows and surrounding objects. The JX Gas pool and spa heater is designed to mount on the wall saving space and making maintenance easy. Normal flues rely on natural draught but this fan powers the JX draught so it can be more compact and efficient. Superior fan-powered design Normal flues rely on natural draught, but a fan ‘powers’ the JX draught so it can be more compact, much more efficient, to have higher flow rates and run cooler. Unique stainless steel Venturi burners Developed to ensure short, sharp, even flame distribution these burners offer long-lasting, corrosion-free operation. The burner design helps generate superior performance from a compact package. They also burn more quietly and more efficiently. JX heating is immediate The JX Series gas pool heaters are so fast they’re able to heat most spas in about an hour, and correctly sized, will heat your pool in 24 hours or less. You don’t need to run the heater for long periods to warm the pool. It’s the nearest thing to ‘on-demand’ pool and spa heating.