The E1 Error Code
The most common reason for an E1 error code to be displayed on your air conditioner's front panel is to remind you that the unit's air filter needs to be cleaned. Many models will automatically notify you of this via an E1 error code display after the unit has been operated for a predetermined number of hours. For example, many Sharp models will display an E1 code after 720 hours of use. Alternatively, you could have dirt or moisture in your front button controls, causing them to stick or not function properly. This can be a common problem with many models of Haier air conditioners, but the issue is not restricted to any one manufacturer. Your air conditioner could also have a defective thermistor, which is part of the thermostat.
For Samsung, the room thermistor needs replacing. This is a device that senses the temperature in the room.
How to Fix an Air Conditioner When It Gives You an E1 Code eHow