Could the Error code be HS? That is high temperature limit. Perhaps you' don't have enough flow,
allowing the heater to heat the water to a temperature higher, than the thermostat setting. Make sure your bypass valve is closed, allowing full flow through the heater. Check your filter pressure differential , and skimmer baskets.
You didn't give your model number, and there are many models. You can go the Hayward website below and select your exact model number and download the manual. The manual will explain each error code.
http://www.haywardnet.com/inground/products/manuals.cfm