Why does my inverter/charger display error code E04?

Why does my inverter read E04?

E04 indicates an over-temperature shutdown. Reduce the loads connected to the AC outlet of the unit. Check that the ventilation grille is not blocked. Check for ambient temperature and move the unit to a cooler location whenever possible. If issue persists, contact Newcastle Technical Support. http://www.newcastlesys.com/submit-trouble-ticket