May 26, 2011 - I have a Hayward H400 IDPL2 heater - when we opened this year I got an IF code so I cleaned out the nozzles and checked the gas levels. I just thought I would share my repair as it looks like it is not widely described on the internet and brought my heater right back to life even. LO Code. Pages 38-41. IF Code. Pages 42-44. AC Code. Page 45. AO Code. Page 46- . 5. When set temp is reached, the control ends the call for heat. The gas. Hayward heater 'IF' fault code as meaning Insufficient Fuel – though the IF code actually . frustration for pool service technicians – is insufficient gas supply. instructions. • If you cannot reach your gas supplier, call the in conformance with applicable local and national codes and regulations. The heat exchanger in your Hayward pool heater is made from the highest quality of copper and nickel.