Hayward H400FDN Universal H-Series 400,000 BTU Pool and Spa Heater, Natural Gas, Low Nox

The Hayward H400FDN Universal H-Series 400,000 BTU Pool and Spa Heater, Natural Gas, Low Nox is a versatile product with a great heating capability. With a natural gas model, it can also be operated on propane but requires a larger propane tank. It has been tested and proven to work well in in-ground pools and spas, including those located in Florida, and can raise the temperature of a 20x40 pool 1-2 degrees per hour while taking about 15 minutes to raise an 8' spa to 102 degrees. The heater sometimes emits steam for a few seconds when it is first fired up while burning off any condensation, but it should not steam for more than that. The heater's longevity is determined by the climate and whether or not it is covered when not in use. The monthly energy cost varies based on fuel pricing in the area, but you should expect to spend approximately $700 per season (June-September) to heat an average-sized pool. The Hayward H400FDN Universal H-Series 400,000 BTU Pool and Spa Heater, Natural Gas, Low Nox has received mixed reviews, but it is a great product that is efficient and effective. Some customers have had a great experience with it over two years without any issue, while others had to replace theirs within five years.