My old Bezzera BZ99s group solenoid no longer seems to be working properly and while it pulls shots just fine, the pressure isnt released after pumping stops and it will do PF sneezes if I dont wait long enough for the pressure to bleed out past the puck.
I have tried removing the solenoid valve to check that the hose to the drip try is clear and also that the solenoid is group to dump path is clear - I can easily blow air through both paths while I cannot blow air through the solenoid from the boiler inlet side.
I also measured the voltage across the live and neutral leads and confirmed that while the pump switch is on, there is mains voltage present plus I tried pumping with the live and neutral leads disconnected the from the solenoid and found no water pumping through in this case.
Finally, I do get water flowing through the solenoid to the drip try after I pump very briefly with a blind filter installed (so that there is only low pressure in the group) but not if I pump for more than a second or so.
None of this has changed after disassembling an reassembling the solenoid (its a T body type, not the flat plate type) and checking that nothing inside it jammed; nor has backflushing with Cafetta (with very brief pumping bursts) made any difference.
It seems the fault is the solenoid valve but it there any way that I can service it (it is the "T" type valve, not a flat base one) or do I just have to admit defeat and buy a new solenoid?
Greg
I have tried removing the solenoid valve to check that the hose to the drip try is clear and also that the solenoid is group to dump path is clear - I can easily blow air through both paths while I cannot blow air through the solenoid from the boiler inlet side.
I also measured the voltage across the live and neutral leads and confirmed that while the pump switch is on, there is mains voltage present plus I tried pumping with the live and neutral leads disconnected the from the solenoid and found no water pumping through in this case.
Finally, I do get water flowing through the solenoid to the drip try after I pump very briefly with a blind filter installed (so that there is only low pressure in the group) but not if I pump for more than a second or so.
None of this has changed after disassembling an reassembling the solenoid (its a T body type, not the flat plate type) and checking that nothing inside it jammed; nor has backflushing with Cafetta (with very brief pumping bursts) made any difference.
It seems the fault is the solenoid valve but it there any way that I can service it (it is the "T" type valve, not a flat base one) or do I just have to admit defeat and buy a new solenoid?
Greg

I guess the issue may also be for thos reading and thinking they can do the same 
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