How to de-scale a KRUPS F 866 Combination Coffee Machine

Posted by kypoth-Alex on Sep 13, 2009 in Hardware, How To Fix ... |

Although not strictly computer hardware related, without coffee could you do a days work? You could probably last a day without your server running, but where would you be if the coffee machine goes down? I’ve also written this article as KRUPS now list this machine as discontinued hence nothing available on their site†. I know I’ve got the manual somewhere, but I always turn to the web for this type of info nowadays.


If your machine has got to the point where it only blows steam through the espresso maker, rather than the trickle of fresh aromatic espresso that you’re used to, then it probably means the insides are blocked with limescale. Follow these de-scaling instructions and you’ll be back to enjoying proper coffee in no time.

What you need:

  • A blocked-up coffee machine
  • De-scaling solution
  • Water
  • A stubby handled screwdriver

Unplug the machine, make sure it is cool and empty of water.

Remove the glass jars, the espresso filter holder and the overflow grid, then turn the machine upside down. Handy tip – put your hand on the filter coffee lid to stop it flapping about.

According to the instructions, you’re supposed to remove the brewing head sieve by turning clockwise with a flat bladed screwdriver. fixkrups2Mine wouldn’t budge, clockwise or anticlockwise, so I abandoned that idea and, using an inkjet syringe, I squirted some descaler into the sieve and left it upside down for a few minutes. If your sieve comes off, happy days, leave it off and carry on to the next step. I reconnected the espresso filter holder and then I turned the machine back over. The stuff started to come through fairly quickly so get ready with the jug to catch any drips.

Pour your descaling solution into the machine, I filled my jug to the metal band just above the 4 cup level and poured that in.

Wait for the fizzing to do it’s business. If you’re using vinegar, this will be at least a couple of hours, anything else and you’ll have to read your label / improvise. Don’t screw the lid on as it will build up pressure (which then explodes everywhere when you open it – trust me). Stand by with a cloth in case it overflows.

When the fizzing has subsided, screw the top on the boiling chamber, place the jug underneath and switch the machine on to brew. Allow the solution to come through the machine.

You could unscrew the steamer tip and put this in the jug to give it clean if it’s dirty. You shouldn’t need to worry about the steamer tube as it’s quite wide and shouldn’t get blocked up but if you want to give the steamer tube a blast, then don’t do it into the half full jug of solution like I did because it goes everywhere. Use an empty jug!

When I used a commercial descaler, there was a lot of foam. Get ready to switch off half way through and discard the solution or your jug will overflow! It might be worth doing this anyway and leaving for a while mid-cycle just to let the solution do its work inside the pipes.

Flush through at least twice with clean water, remembering to release the pressure (by switching to steam) before you unscrew the lid. Let it cool for a minute or so with the lid off, then be very careful and slowly pour the water into the chamber as when it’s hot it will bubble up if you pour too quickly.

Once you’re happy that the water coming through is taint-free, you’re ready to enjoy real coffee again.

What de-scaling solution should I use?

Of course there are various manufactured descaling solutions. Whilst fine and I have used them in my kettle in the past, I’d rather keep those for doing the bath and sink as the big “Irritant!” label on the side is a bit scary. If your machine hasn’t been descaled for ages, you may have to use a commercial cleaner (and there are specialist coffee machine ones available), otherwise white vinegar works fine but is a lot slower so needs to be left in for longer.

What I did find was a great community site called Diplodocs, which hosts all sorts of manuals, from big things like cars to small appliance-y type things. Bookmark it as it’s bound to useful one day. On this site there’s a manual for an F867, which looks identical to the F866 apart from the addition of a clock.

Disclaimer: The eagle-eyed among you will have spotted the handle on my filter holder is broken. I know! And I know this is supposed to be a fix-it site ;) . However, some things just can’t be glued and are too small or awkward for plastic welding. But it doesn’t really matter as I just use a cloth when it’s hot. You don’t have to tighten it up to the max level – I discovered from the manual above that this has no impact on the strength of the coffee, anywhere within the marks will do. I thought it did make the coffee stronger, which is why I always tightened it to the max, until one day it snapped! New handle is £10+p&p, but I’ve managed without so far.


chris curtis
May 3, 2012 at 7:45 pm

Thanks for the Krups F866 fixing instructions – exactly what I was after! I couldn’t undo my sieve either so its presently soaking in white vinegar until I get some de-scaling solution in!

Jul 11, 2013 at 10:48 am

Sorry it’s taken so long to reply, glad you found the post useful :)



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