If you notice a code such as E5 come up on the display of your air-conditioner, then your system is letting you know that there is a fault. This fault code can greatly help our technicians when they come to fix your system so be sure to add any codes you see, along with the brand of the air-conditioner, to your email when you book. These can show up in the small black display shown in the picture or in the middle of your air-conditioner, depending on the brand. Fault codes can also sometimes be found on your remote controller or digital thermostat as well.