Hi Folks,
We Have a La Pavoni UBAR-V2 machine. Water is aggressively squirting out of the drain port on the right head, blowing the tubing off- big mess. The repair people were over from Durango a couple of days before this started. Now the head wont flow water, only the drain, insistently. Any guesses as to what part to take off to get this working right again?

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This sounds like a problem with the solenoid valve. I would say that it's stuck either open or closed but neither makes sense for what's going on. Is it only spraying out when you push the brew button or is it doing it continually?

When the valve is closed, it keeps boiler water from entering the group head and opens the drain line. When you press the brew button, the valve opens, letting water from the boiler enter the group and blocks the drain line so that it flows through the shower screen. When you stop brewing, the valve closes again, stopping water from the boiler and letting the excess water and pressure from the portafilter exit the drain.

If the valve was stuck closed, nothing would happen when you press brew but nothing would come out of the drain either. If it were stuck open, water would continually flow out of the group head from the shower screen but not through the drain line. It sounds like maybe the hole to the shower screen is blocked and the valve is malfunctioning and sticking halfway. That's my best guess without seeing it.
I'm with Ryan... that valve is probably hosed. Is there maybe a problem with the sealing surface on the back side of the solenoid (the inner moving bit)? That surface has to seal on the drain port's seat to keep water from flowing out when the valve is in the open position. Maybe a little debris on that ruby-colored bit?
Would also agree- most likely the solenoid has some problem- jamed open. It would be the first time I have encounterd a valve stuck open, the electric current sent to the parker-solenoid opens, then shuts the valve. For it to be jamed open seems unusual. However, I would also add there is a chance that there is an intenal blockage in the group. I am nots ure what kind of group the laPav uses, but in Astoria machines sometimes a blockage occurs and the result can be similar to what you describe. There are two ways of normally clearing a blockage- both involve using compressed air.
Thanks All,
I removed the head and the whole going to the screen was blocked but thanks to paper clip and cleaning solution I was able to get the head looking better. I am still not sure why water was continually shooting out of the drain hole. I replaced the clear drain tube that was not staying on with fuel line tubing, which is stronger but prevents me from seeing drainage. So when I get time I am going to have to pull the lower drain line and see if I have steady flow still emerging, but I am thinking that is not happening. But I bet that you are all right that the solenoid is screwed.
Jude

Ryan Soeder said:
This sounds like a problem with the solenoid valve. I would say that it's stuck either open or closed but neither makes sense for what's going on. Is it only spraying out when you push the brew button or is it doing it continually?

When the valve is closed, it keeps boiler water from entering the group head and opens the drain line. When you press the brew button, the valve opens, letting water from the boiler enter the group and blocks the drain line so that it flows through the shower screen. When you stop brewing, the valve closes again, stopping water from the boiler and letting the excess water and pressure from the portafilter exit the drain.

If the valve was stuck closed, nothing would happen when you press brew but nothing would come out of the drain either. If it were stuck open, water would continually flow out of the group head from the shower screen but not through the drain line. It sounds like maybe the hole to the shower screen is blocked and the valve is malfunctioning and sticking halfway. That's my best guess without seeing it.
Just get on with it and take down the solenoid valve and split it you will probably find it is jammed because it has not been backflushed with detergent or has a build up of limescale both of which can be cleaned off and the valve simply rebuilt but make sure the machine is cold and water turned off before any attempt to remove the valve.
Alan

Jude Schuenemeyer said:
Thanks All, I removed the head and the whole going to the screen was blocked but thanks to paper clip and cleaning solution I was able to get the head looking better. I am still not sure why water was continually shooting out of the drain hole. I replaced the clear drain tube that was not staying on with fuel line tubing, which is stronger but prevents me from seeing drainage. So when I get time I am going to have to pull the lower drain line and see if I have steady flow still emerging, but I am thinking that is not happening. But I bet that you are all right that the solenoid is screwed. Jude

Ryan Soeder said:
This sounds like a problem with the solenoid valve. I would say that it's stuck either open or closed but neither makes sense for what's going on. Is it only spraying out when you push the brew button or is it doing it continually?

When the valve is closed, it keeps boiler water from entering the group head and opens the drain line. When you press the brew button, the valve opens, letting water from the boiler enter the group and blocks the drain line so that it flows through the shower screen. When you stop brewing, the valve closes again, stopping water from the boiler and letting the excess water and pressure from the portafilter exit the drain.

If the valve was stuck closed, nothing would happen when you press brew but nothing would come out of the drain either. If it were stuck open, water would continually flow out of the group head from the shower screen but not through the drain line. It sounds like maybe the hole to the shower screen is blocked and the valve is malfunctioning and sticking halfway. That's my best guess without seeing it.

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