Common hot tub error codes include Flo or FLC, Dr or DRY, COOL, SnA or SnB and OH, according to Swim University. Learning the meaning of these codes can keep hot tub owners from having to call a repairman.
The error code Flo or FLC indicates a problem with water flow and can sometimes be fixed by replacing the hot tub's pump after confirming it is not receiving proper voltage. If this does not fix the hot tub, the problem requires contacting a professional repairman. The error codes Dr or DRY indicate the heater has inadequate water flow, which may be fixed by adding water if the hot tub's water level is below the fill line.
OH is an error code indicating the tub is overheating, meaning the temperature is above 108 degrees Fahrenheit. This may be fixed by replacing the temperature sensor. If the water is truly above 108, avoid getting into the hot tub.
COOL is an error code indicating the tub is more than 20 degrees Fahrenheit cooler than it should be, and it can be fixed by placing the cover on the hot tub and letting it warm up. SnA and SnB both indicate a problem with a specific sensor and can be fixed by checking the sensor connections to the circuit board and replacing the sensors as needed.