What does the pr code mean? I am getting this after draining my tub and refilling....

That error means that the tub was drained. Reset the controller and it will be fine.

if no drain at bottom usually with hose connection on it use a sump pump or syphon make sure power is off until fully refilled

Are the pumps primed, the code represents that the pumps are being primed and should only stay on 2 - 5 minutes. If the pumps are not primed then you may have an air lock or dirty filters. You need to release the air or clean or replace the filters and your pumps will prime.

Hi, I am not a hot tub expert and I don't know what PR status is or what PL on the display means . However I did a quick search for you and have a web address that might help you find a solution.
http://www.spacare.com/troubleshootingguideforspaandhottubs.aspx
Hope it helps you
Regards
Steve

please follow this steps and fix it. God bless you
If the unit won't start, make sure power is on at the electrical panel or the electrical panel . Then test the pump and the motor. Check for and repair broken wires or loose or corroded terminals. If necessary, have the pump switch control tested and serviced professionally.
If the jets do not work, clear a blocked water intake of hair and other particles (see below) or replace a broken jet (see below).
If the water in your spa or hot tub is too hot or too cold, check to see if the high-limit reset switch has been tripped and, if needed, reset it. Adjust the thermostat setting and have the thermostat serviced if the problem persists. If necessary, test and replace a faulty heating elements

follow this steps and fix it. God bless you
If the unit won't start, make sure power is on at the electrical outletor the electrical panel Then test the pump and the motor. Check for and repair broken wires or loose or corroded terminals. If necessary, have the pump switch control tested and serviced professionally.
If the jets do not work, clear a blocked water intake of hair and other particles (see below) or replace a broken jet (see below).
If the water in your spa or hot tub is too hot or too cold, check to see if the high-limit reset switch has been tripped and, if needed, reset it. Adjust the thermostat setting and have the thermostat serviced if the problem persists. If necessary, test and replace a faulty heating elements

Make sure the spa is not on sleep mode "SLP" or economy mode "ECO". Without knowing what type of spa you have it's hard to diagnose but it's possible your pressure sensor or high limit sensor it temporarily out of balance. If that's the case, it will resolve itself. If the problem persists you have a faulty faulty pressure switch or sensor.

The dr error code is for "dry". Meaning that the control system is not sensing that water is flowing through the heating element.

With a new spa, and you just having drained it , it is probably an air locked pump.
What this means is that you have a small constant circulation pump with not much power, that got ait trapped in it when you drained. When you went to start back up, this "air lock" prevented the pump from fully priming.
Power down the spa at the breaker. Remove the filter element.Stick a garden hose with lots of pressure into the skimmer hole and open the hose valve to let water inject into the skimmer.
Restore power to the spa and check operation.
If after attempting this a few times you still get the code, there is an issue with your flowswitch, or with your circulation pump.
With a brand new spa, id like to hope that you just have an air lock.

Good luck

Probably a ground Id check that water did not get into any ele.system