Random error codes Jandy LT400-N-L heater


New member
Feb 27, 2016
Santa Clarita
Hi, I'm having an issue with my Jandy LT400N-L pool heater communicating with my iAqualink 2.0 control center. When I'm power cycling the heater, every 4th to 7th time, I will get random error codes on my heater such as a flashing service light with either Air Flow or AGS. When I disconnect the wire harness (from fireman's switch to aqualink) that connects the heater to the iAqualink and manually power cycle the heater while running the filter pump, there are absolutely no service codes and the heater runs perfect. I want to know if anyone has run into a similar problem with a similar setup. Last year, I wasn't having any problems with the two devices communicating. I've been told by one pool professional that the Zodiac/Jandy 7727 Dual Thermostat control board attached to my heater may solve the issue. Any advice would be appreciated.

Also, I've already gone through the troubleshooting flow chart that Jandy provides for this heater and everything check out good with the voltages.