My hot tubs pump won't start by itself but i can manually turn it on using the button. At first when i turn the gfci on it'll say 20 then 00. Then it'll display the set temp which is 100. Imediately after that the pump should kick on and it doesn't. But if i press the jet button the circ pump kicks on and stays on untill the tub reaches the desired temp. But once the temp drops below 100 the pumps won't kick on and i get fl for flow on the display. I just replaced the heater with factory spec heater and also replaced the pressure switch with factory len gordon switch and is calibrated properly. The only problem is that the pump won't start by itself. I should also state that i have a balboa spa pack hs55. Any help would be appreciated. Thanks.