I have a Giotto Evo.
Machine is about 15 months old / has seen normal domestic use / has been cleaned regularly
Past couple of weeks I have noticed the drip tray needing emptying more frequently. Subsequently noticed that water is flowing out of the expansion / OPV valve outlet (not the 3 way valve) into the drip tray
when I’m pulling a shot.
I know that one of the things the expansion valve does is help to bleed off a bit of water as the boiler comes up to pressure, but should not really drip too much besides that
From my limited understanding I’m guessing it could be something like:
1 – OPV (if it is even adjustable for ones attached to a rotary pump system?) is set too low or the setting has moved somehow
2 – OPV / expansion valve has gunk / scale in it that is causing it to open under pressure
3 – brew pressure (ie the setting on the rotary pump itself) is set to ~12 bar and is hence forcing the OPV to open when pulling a shot
Am I on the right track with possible causes? Any advice appreciated
NB - coffee still tastes good
Machine is about 15 months old / has seen normal domestic use / has been cleaned regularly
Past couple of weeks I have noticed the drip tray needing emptying more frequently. Subsequently noticed that water is flowing out of the expansion / OPV valve outlet (not the 3 way valve) into the drip tray
when I’m pulling a shot.
I know that one of the things the expansion valve does is help to bleed off a bit of water as the boiler comes up to pressure, but should not really drip too much besides that
From my limited understanding I’m guessing it could be something like:
1 – OPV (if it is even adjustable for ones attached to a rotary pump system?) is set too low or the setting has moved somehow
2 – OPV / expansion valve has gunk / scale in it that is causing it to open under pressure
3 – brew pressure (ie the setting on the rotary pump itself) is set to ~12 bar and is hence forcing the OPV to open when pulling a shot
Am I on the right track with possible causes? Any advice appreciated
NB - coffee still tastes good

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