How's your pool spa? Is it working now? Not exactly sure about what's the problem unless one can see it. Something may be clogging the mechanism, maybe it needs cleaning, or part of the jet motor is broken. Best way is to have it checked by an expert pool technician so that whatever problem is present, proper maintenance is applied. How long has this problem been going on, by the way? Did you just notice it or has it been there for quite some time?
Some solutions that may help:
Air got into the system after draining - bleed the air out so it will get fixed.
Check the pump, take it apart and check for obstructions
Clean out the filter
Check for closed valves and open them
Maintain recommended water level to prevent air from getting in.