What is a realistic espresso machine maintenance schedule?
Daily: water backflush, wipe the wand and screen. Weekly: detergent backflush and a screen soak. Every few months: strip the grinder burrs and check the gasket. Annually or by water hardness: descale and replace the group gasket and shower screen.
Daily, and this takes under two minutes: purge the group for a second or two before and after pulling, knock out and wipe the basket, water backflush with the blind basket if your machine supports it, wipe and purge the steam wand immediately after every steam, and empty the drip tray when it is more than half full. Nearly all of the hard maintenance problems people face are the accumulated cost of skipping this.
Weekly: a detergent backflush followed by several plain water flushes and a discard shot. Remove and soak the shower screen and, if it is easily removable, the dispersion block. Soak the portafilter and baskets in detergent solution, keeping the plastic handle out of the water. Give the grinder chute a brush out. Wipe down the counter and the mat.
Monthly to quarterly: strip the grinder burrs and clean them properly. Check the group gasket by watching how far the portafilter handle travels when you lock it in, and inspect the basket holes against a light for blockage. Descale the kettle if you brew filter too. Clean the water tank and any tank filter, since biofilm in a tank is real and unpleasant.
Annually, or more often on hard water: descale according to your machine's procedure, replace the group gasket and shower screen as wear parts rather than waiting for them to fail, and replace any water filter cartridge on schedule. On a machine with a pressure gauge, this is a sensible moment to check that the pump is still delivering around 9 bar at the group during a shot and to adjust the OPV if it has drifted.
The honest note about frequency: these are intervals for daily use with a machine you intend to keep for years. If you pull two shots a week, scale everything back proportionally. But do not scale back the two habits that cost nothing and prevent the most damage: purging and wiping the steam wand immediately after every use, and using water that will not scale your boiler. Those two are worth more than everything else on this list combined.