Bezzera Strega Descale Procedure

A haven dedicated to manual espresso machine aficionados.
EspressoForge
Sponsor
Posts: 1350
Joined: 16 years ago

#1: Post by EspressoForge »

Just throwing this up here in case it helps anyone else. I completed a much needed total descaling of the Strega last night, shots are much improved, but likely has a lot to do with a new RO system I just installed!

Anyway, here's what I did to descale both the boiler and HX:
  1. Heat up machine as normal to at least 1 bar then turn off
  2. Drain boiler completely using hot water tap - after air starts coming out at approx 1.2 liters of liquid, tip machine backwards carefully while draining the last 100-150mL. There may still be a bit of water in the boiler, but it shouldn't be enough to matter.
  3. Mix up 3 liters of water & citric acid powder (6 Tbsp) - I got this in the canning section at Walmart, but you can get it online or at beer making suppliers too. 2 liters should be sufficient if just descaling boiler
  4. Replace water in tank and turn back on machine, pump should fill up the boiler after a minute or two.
  5. Wait for machine to come up to pressure, then flush additional descaling water through the HX a couple times.
  6. After this I tried to tilt the machine to see if I could fill the boiler a bit more, but no luck, so I left machine on and waited about an hour. Citric acid works better when hot.
  7. Turn machine off and drain boiler completely as above, you'll notice some nice blue/green water coming out. This is normal.
  8. Change out tank water with fresh water, at this point you can use pure RO water without tap water or minerals added or even distilled water since it will ideally be better to have very low mineral content water. I wasn't worried about messing up the boiler/elements with pure distilled water since there should be a little water left in the boiler after draining to mix.
  9. Turn back on machine and wait for temp to come back, then flush HX until water looks clear and tastes good.
  10. Flush a bit more through the hot water tap looking for the same clear, no scale pieces coming out, and water to taste good.
  11. Pull a shot or 5 to confirm all is working.
Any comments or suggestions welcome. If I could have found the boiler fill switch, I would have attempted to get the boiler to overfill, but ended up it was late and I didn't take more than the top cover off the machine.