by Bluecold on Tue Mar 03, 2009 8:23 am
First i'll assume the pump is working.
The water from the pump to the coffee goes past the opv, into the boiler, past the three-way valve and then into the group.
The three-way valve is a handy little gizmo to release the residual pressure above the coffee so if you release the portafilter, nothing gets sprayed with coffee and hot water. But, by releasing the pressure, some coffee and grounds go up, through the showerscreen, the group and the three way valve out in the driptray.
So, if you don't clean those areas, they can get very dirty indeed. Those areas are cleaned by backflushing. You haven't backflushed in 1.5 years. If one assumes 3 shots a day, that amounts to 1642 times a little bit of coffee. Without cleaning. So I think your grouphead and your three way valve are clogged up.
Time to take out the screwdrivers, the detergents and some old toothbrushes!
LMWDP #232
"Though I Fly Through the Valley of Death I Shall Fear No Evil For I am at 80,000 Feet and Climbing."