When your Saltron Retro power supply is flashing “Lo” and hours with the yellow light lit it can mean a few different things.
First, your salt levels could be low. Use the SafeDip or SaltDip if you have one or use test strips to measure how much salt you have in the pool. Once you know the PPM (Parts Per Million) off salt in the water you can use the chemical calculator at http://www.poolcalculator.com/ to figure out the correct amount of salt to add to your water.
Second, it could be that the water temperature is too low for the Retro to function correctly. It is not recommended to use the Saltron Retro in water temperature is under 65F.
Third, your cell may be nearing the end of its life. The Saltron Retro cell is rated to last about 5000/hr before needing to be replaced. You can order a replacement direct though our website at http://solaxx.com/saltron_retro_parts.php .