Changing Filament problems

[Jonesy77]

I've had my A20T for 2 weeks and really find the instruction manual not much help, if I'm honest, so have come on here hoping for some guidance as to what I'm doing wrong. Really frustrated with this machine as 2 weeks in still not managed to successfully print anything of note yet.

I am having trouble getting the machine to print from one of the extruders, I think its called E2 in the manual - (its the one on the right as you are looking at the machine), E0 & E1 seem to be working ok. Could this be a problem with the heating element in the Extruder Head? Is there anything I could check to see if there is a blockage?

I have worked out how to change the filaments using the Prepare > Preheat PLA options and wait for it to say Change Filament then I can see the filament retract back up the tube to the extruder called E0 (although just to add to the confusion the display screen says E1). I have also worked out that I need to change the mixer settings (from 100%, 0%, 0%) to 0%, 0%, 100% to enable the filament change on E2. What I cannot seem to do is set the mixer setting to 0%, 100%, 0% to enable me to change the filament on E1 and have had to resort to setting the mixer to 50%,50%,0% so it retracts two filaments at the same time. Am I doing something wrong or missed something obvious to be able to set the mix as 0%,100%,0% - it seems a bit user un-friendly having to do all this and surely a better way would be to get to the Change Filament option and be able to select which out of E0, E1, E2 you would like to change.