Faema Espresso Grinder Burrs - 54 x 31 x 8 Brand_Aeropress or have a qualified technician

or have a qualified technician install it

some older Astoria's actually use both the 1/4" x 3/8" and 3/8" x 3/8" sizes in different locations

and installing it backward will throw off dosing even though the flowmeter appears to be working normally

not a grinder malfunction

normal wear and tear

Faema Espresso Grinder Burrs - 54 x 31 x 8 Brand_Aeropress or have a qualified technicianFaema Espresso Grinder Burr Set, 54 x 31 x 8 mm Replacement flat burr set for Faema coffee grinders, right hand rotation. Fresh burrs restore grind consistency and particle uniformity when your shots start tasting flat or your grind size drifts. SPECIFICATIONS Outer burr diameter: 54 mm Inner burr diameter: 31 mm Thickness: 8 mm Rotation: Right hand Accepts only a 6 mm wide screw head fastener (some Faema grinder versions use a larger screw head)