make sure to fill the spa through the grey filter standpipe always. this will help purge the air out of the system. second as stated earlier, flip on the 30 amp breaker first, run both pumps for a minute or two, use your diverters to get water through all jet menus, make sure you have good circulation from the floor return, then flip on the 20 amp breaker. you may want to leave the filter off of the grey standpipe until the spa has reached temp just to be sure the problem is not caused by a bad filter, another good trick i use is to flip on the 30 amp with hose running full blast down the grey standpipe, this helps purge out air in the circ pump and heater. If all this does't work, open your equipment door and work the air bubble out of the vinyl tubing feeding the circ pump by sqeezing the tubing. For some reason some hot springs are more tempemental when it comes to drain and refill. your dealer should be pretty skippy with all this stuff too