FL1 code on sweetwater spa is flashing. I have cleaned the filter and have the same code. The spa is heating but I am not sure if the water is filtering. At higher temp. the spa will turn on and off frequently. Every 5 min. Help

Try running it with out a filter, I have seen many filters that were "just cleaned" that water does not flow through them properly. FL1 is a flow error, try no filter, then check your pressure switch for proper activation, check the wires to the switch.