Greetings from GoVacuum,
Ahh yes, the Silver Moon. One of Miele's best made vacuums ever! So good that out of all the different vacuums that I could of chose for my home, the Miele S558 Silver Moon was the one I chose.
When you're Reset button is flashing, this simply means that it's time to replace the HEPA filter on your vacuum cleaner. Miele included this feature on their upper end models to alert the user when their filter needed to be changed.
The Miele Silver Moon uses Genuine Miele S-Class HEPA Filter for S300i/S600i, and Miele S7 Uprights. Miele Part # 04854915 (replaces 04854911)
Which can be purchased from GoVacuum for $52.95 with free shipping.
Once you have installed the new HEPA filter, simply press down on the flashing Reset button to restart the 50 hour internal timer inside. Miele recommends to replace this filter after every 50 hours of vacuuming.
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Thank you very much,