We have a Sundance Hawthrone 680 series. I think it’s a 2011 or 2012 model. We have been having some trouble with our hot tub. Every couple of days it seems to give us an error code FL1 and begins losing heat. Pump 1 will no longer work, only pump 2 will circulate. This will continue for a few hours and then eventually pump 1 will turn back on, heat up and be back to normal for a day or two. This is concerning because sometimes the heat has gone done to 80, but again the hot tub usually fixes itself. Sometimes we will turn off the power breaker and this will fix the problem. When I tried resetting the hot tub to the factory settings by turning off the power for 5 minutes. The numbers 599 flashed on the screen and then it just showed the temperature we had the hot tub set at. We have just replaced the filters with brand new filters. I also had the water tested and have balanced it. Do you have any other suggestions I could try to fix this problem? Thanks for your support.