View Full Version : Gaggia classic blocked

14-07-09, 05:09
Hello all!

This morning I tried to make my regular coffee and found that the machine is completely blocked. Pressing the coffee button creates a lot of noise that then dies down to a whirr. Hot water/steam flows happily enough out of the side jet if I unscrew the valve.

I've taken off the shower head and removed loads of crud from underneath it but still no luck. Should I try to remove the next layer? I've tried to unscrew the bit underneath the shower head but the hex-screws are just too tight!

Any advice greatly appreciated - I'm having to walk to campus for my coffee!

14-07-09, 07:03
Sounds like a case of scale.
Have you descaled the machine recently?

I would recommend backflushing after each use and descaling at least every 3 months.

Do you get a stream of water flowing back into the water tank?

14-07-09, 07:29
Thanks for the quick reply - didn't know there was such a thing as backflushing before discovering this forum! The machine hasn't been descaled in a very long time. I've noticed there's loads of coffee grinds *behind* the shower head and in the four small holes in the back plate behind it.

Should I attempt to remove the hex screws and take off that plate (part 61 on the service diagram)? I don't see how I can backflush or descale without first getting it into a state where at least some water is flowing.

Thanks for your advice,


17-07-09, 08:31
Yes, take off the shower screen and then the shower plate (22 and 24 in the diagram you can find in the link below). Poke a straightened paper clip in the hole to see if there's anything blocking it (scale). You can they test again to see if you have any flow. Probably needs a good descale or two so do that with the shower screen off.

If you feel confident and competent doing so, then you can take the boiler out and open it up as it is much easier to clean out scale that way, rather than expect it all to fall out that tiny hole. Don't immerse the top half of the boiler in liquid as it could short out the heating elements (as I found out recently). Also make careful note of any wires you pull off, preferably take pictures first. Take reasonable precautions not to electrocute yourself!


Have a look at the OPV as well (part 28), you can take it apart and descale it too although it shouldn't be the cause of your problem.

No, you won't be able to backflush without some flow. Take it you have the blind filter basket and some Puly Caff detergent for this? Use the Puly Caff to clean up the portafilter, basket, shower screen and plate, then scrub up the group head area too and do this regularly. If you can't undo the hex screws then try a socket set with hex sockets for more leverage. Or make do with some kind of metal tube as an extension over the allen key.

Check out some of the cleaning and descaling guides eg Home Barista. Happy Donkey or other sites can supply the materials which are a good investment to keep the machine running.

18-07-09, 12:45
I've taken the shower plate off (had to run a large screw down the centre hole to do it) and water's now flowing neatly from one side (mysteriously there appears to be no hole on the other side...)

Never heard of backflushing before, so own no blind filter basket nor Puly Caff. Will have to look at getting some. Do you think it's worth replacing the gasket while I'm at it - it will have been in service 5 years by now!

Thanks for the advice!

18-07-09, 03:19
Absolutely worthwhile changing the gasket/seal.
Ideally change this every 6 month to a year to keep a good pressure buildup, forcing the water through the grounds.

19-07-09, 10:17
All sorted - after enough cleaning of the group head etc. and descaling water is now flowing through the machine unimpeded.

Haven't changed the gasket as it still seems to be in good working order and isn't leaking, though I will order a spare at some point along with kit for backflushing.

Thanks to both of you for your help