Possibly the "Heater Flow is Low" (HFL or HL).
During Heating, this message indicates a Possible Low Flow Condition. There may Not be Enough Water Flow through the Heater to carry the Heat Away from the Heating Element. Heater Start Up will begin again after about 1 Min. Check for Water Level, Flow Restrictions, Closed Valves, Air Bubbles, and Pump Prime, or contact your Dealer or Service Organization.
Check for All of the following Conditions:
1. Low Water Level.
2. Blocked Suction Fitting.
3. Blocked Skimmer.
4. Dirty Filter.
5. Too Many Closed Jets.
6. Closed Slice Valve.
7. Heat Related Pump Not Running.
8. Heat Related Pump Not Primed.
For all Diagnostic Messages, click on below link.