Is it only low water level? Generally there is no beep with low water level except for the single beep when first powered up. It will beep if the cause is the water damage indicator and too low is flashing and too high is on solid. Too low only, if on immediately after the regular start up means the settings were erased, usually by a power surge or harsh switching and that can be reprogrammed if you send it in.
Tunze USA LLC
2121 Cole Springs Rd
Buda TX 78610
Send the controller, pump and power supply as well as a copy of the receipt with current address and phone number, I usually complete a repair within a day of receipt. On water damage we make our best effort, but it is not always repairable, it will depend on location and extent. The most common water damage is caused by plugging in the power supply tip after it landed in water and this is usually repairable.