Good day all!! I really need your help.As an auto mechanic I think I know in general how things work.Anyway I have a Jacuzzi Z145 with a Balboa r-574 controller.It has developed an issue where it flashes between the temp and the code fl.I understand this means that there is some type of flow issue.It has four modes of operation..low,low w/light,high,high w/light.When I push the button the high speed comes on then the heater.It will run 30 minutes and then shut down.Both high and high with light work.When you shut the pump down the heater goes off as it should.You can turn it right back on and all works on high.Check for loose connections etc. found nothing.If I close the little contact relay marked low speed(manually with a plastic probe) the low speed pump will come on and run.The heater comes on and shuts off as it should.So my summation is something is either telling the motor to come on,and the board thinks its on and the flow switch is not getting any pressure so I get the fl and temp reading alternating but can still push button to high speed and it comes on because it thinks its already running on low so it goes directly to high speed or I should stick to cars.Also as some on this forum have suggested I have new filter,tried no filter and setting/jumping pressure switch all of which does not change condition.So what is causing this relay to not close?Its hot there is power or because the tubs 7.5 years old maybe the board is on borrowed time?Any help is greatly appreciated my wife and I love the tub and I just want to fix it once.Thanx