[GiovaD]

Firstly don't run the pump for several minutes at a time they are only intended for short bursts./

It looks as if the OPV is stuck but releases suddenly then shuts again ? Try running again and watch the OPV / hose as the pressure drops, is there a small shot of water returning ? Is the adjuster the in the opv the slotted type or the hexagon centre or both ? Has / do you de-scale the M/ch ?

Initially you could try a strong d-scaling solution carefully dripped / poured into the OPV and leave it to soak OR remove it and soak it in a container of -de-scaler . Take care not to force/ strip the slot or hexagon or you will need a new OPV. Sort the OPV first :good:

The opv is locked I believe, the hose is quite dry and also the barbed fitting is dry and shows some white powder as I could tell. I definitely want to open the boiler and descale it part by part. As of now the machine doesn't show any problem: solenoid valve is working perfectly, flow at brew head is very good, also if I completely open the steam nob and press the brew button water comes out from both ends (brew head and steam wand).

It's very hard to tell what you are doing with the steam valve during the video but it needs to be left alone when checking the brew pressure. If you open the steam valve, it is going to remove / reduce the pressure at the brew head. Have you taken the 17mm nut off the top of the OPV? (the V in OPV is valve, so it's not an OPV valve)

In the video I was opening and closing the steam nob in order to simulate a dynamic flow (as with a coffee puck) and as I expected the pump behaves very odd. In fact when I open the steam wand, the brew pressure INCREASES, together with the loudness of the pump.

 

[GiovaD]

Can't quite explain why the pressure would bounce around once the steam wand is opened up, but that might be by the by.

Yeah that I believe to be maybe the little rubber ball inside the pump or some orings that maybe are worn out, I don't really know but I do believe it's strange. Also while brewing sometime I hear it "pulsating" and I can see a difference in the flow while extracting.

blind portafilter in there

There is no flow coming out of the OPV valve, and no I cannot unscrew the Hex head with the barbed end, it's somehow stuck.

Why as the pump got cable ties around it?

That I don't know, I bought it second hand like that. I'm planning to set the pump free from those zip ties as soon as possible

Why is the boiler element disconnected

Because I didn't want to burn myself and there was no need to heat the boiler since I was only testing the pump and the opv. (I have already done the same exact test with my pressure gauge-fitted-portafilter with boiler turned on and did not behave any differently)

Question: have you had experience of a machine with faulty pump? Is that a problem that may involve the pump seals wearing off?

About the OPV I'm definitely going to open up the machine and the whole boiler and replace all seals and descale everything real good, that includes the opv valve.