Drain valve: Turn the breaker to the spa off and unscrew the valve then pull it out from the base of the spa. You will attach a hose to the valve and let the spa drain. Once done screw the cap back on and push into spa then refill.
Bleeder valves: If a pump has an air lock and is not running jets then turn the breaker off. Take a flat head screw driver and unscrew the valves, let the water flow out until it is a steady stream, tighten valve and turn the spa on to see if the jets will work. Repeat the process until the airlock is gone.
Valve location
For Spas without bleeder valves: Turn the breaker off first, you will then need to take the front panel off. There is a clear tube coming out of the pump with a clamp on it. Loosen the clamp and pull the tube off, wait until water starts shooting out to reattach the hose. Turn the breaker on and ensure that it is working.