FL code with Great Lakes spa ...Pumps won't run and tub is cold... light won't even come on.

The pump might need to be serviced, look at the pump for water damage that's a sign it needs repair= bearing and a shaft seal can spark it back to life. and if you are handy you can check the power going to this motor.
Jay the pool pump repair guy longwood fl

check all fuses and breaker

Balboa Direct has an excellent error code listing on their site.

Normally f2 is not an error code.
It is informing you that you are in a "Filtration" mode. In this case Filter Mode #2
But, if we knew what make & model of the control system you have, will assist us better in helping you. Spa manufacturers normally do not use their own proprietary control systems. They will use a 3rd party vendors unit & install them on their spa.

nope dont doo codes..

this is a water flow code check to make sure all valves are open

'Fl' means that there's insufficient flow of water through the heater, or non at all.

1) Check the water level - top up if low.
2) Ensure that all jets are open and flow water - if they don't you may have a pump issue.
3) Remove the filter(s) and see whether or not this clears the fault, if so clean or replace the filters.


Regards,
Ian.
http://hottub.synthasite.com

check to see that the flow switch is working properly, it may not have enough flow on low speed to allow the heater to turn on. Make sure your filter/s is/are clean. If you have a pressure switch instead of a flow switch, it may need to be adjusted or replaced.

tub is in sleep mode usually to change u must press temp button then light button you want to b on standard mode STD