Thank you, we do work for insurance companies. We need to establish if the inverter can be repaired or if it should be replaced. The error code doesn't help with pinpointing the exact fault. We worked on a kodak inverter yesterday with E51 - either surge or overload. The inverter was fitted with a surge arrestor and when we tested the load it was still within range. I spoke to a third party repairer that mentioned that he had a tool or software that he could plug into the inverter to do a full diagnostic test, similar to how you can check the error codes on your car.