I own and service several EM6910 machines at home and work over the past few years and thought i should pass on some info i have learnt about this machine.
For the last two years i have taken the work machine home every 6 months to descale it with a 20% solution of citric acid and replace the collar or seal as needed.
Its been three years now and i have noticed that the steam quality has continued to degrade even though i was descaling it.
At this same time i also purchased two more em6910's off gumtree for $40 and both werent working due to blocked steam.
This time i decided to remove the steam thermoblock from all of them and have a look inside.
This thermoblock had citric acid sitting in it for two days and it didn't do anything.
Next step was to use something stronger and much more controversial. Hydrochloric acid.
Its really hard for me to get a photo of inside the thermoblock but i promise it made a massive difference.
Sorry, i didnt realise my photo links didnt work the first time.
rawill and topshot like this.