Hello, I'm experiencing an issue with my dispensing pressure. Everything was working fine until I had to unplug my Marzocco to move it. I also moved the external water pump and blew some canned air on it to dust it off. The next day, after moving the machine back and placing the water pump to its spot on the floor, I turned my Marzocco on and everything seemed fine until I pulled a shot- I was only getting 5 bars of pressure. I tried adjusting the regulating screw on the external water pump, but not matter how much I turned it clock-wise or counter clock-wise it wouldn't increase or decrease the dispensing pressure, it still stayed at 5 bars. Was hoping somebody might have some insight on what my issue might be, thank you so much!!

To recap, you should find a pressure adjusting screw similar to the one shown below:


From Procon exploded view; also see Adjusting espresso machine's rotary pump brew pressure?

Counter-clockwise = more water passes from outlet to inlet through the bypass valve = lower pressure. Clockwise = less water passes from outlet to inlet = higher pressure. The adjustment is fairly sensitive, i.e., one-half turn should produce an immediate increase in pressure. If not, the relief valve could be stuck; it's also possible there's an obstruction along the way to the brewhead (e.g., the gicleur could be clogged with scale). To confirm or eliminate the pump as the cause of the problem, tee in a pressure gauge immediate after the pump. It will show the pump's output directly.

Hi Dan, it's definitely the motor pump, it's not even working- the only pressure i'm getting is from my Culligan water system thats connected to the pump. I'm hoping that means it might just be a fuse, but i'm not sure where that might be located, I do see an external capacitor, and also a white box where the electrical cord comes out from- that can be taken off. I'm in the process of printing off a technical manual for the Marzocco & motor pump...

-brian

assuming that the machine was not sitting for a while before/during the move repositioning
remove the pump from motor and check that the shaft of the pump is moving smoothly (however with the water lines connected you will be feeling some resistance),
if so while you hold the pump have somebody else BRIEFLY push any brewing button
to see if the motor spins if so electricity is arriving to the motor and you get a full voltage (220v or whatever is the building voltage)
if not check the wires from machine to pump
reconnect the pump
and push a brewing button again
no results? your pump could be bad
slowly starting could be the capacitor

Hi stefano.. There is no spinning at all on the motor while brewing and all wiring seems to be connected just fine. Could blowing canned air around it have caused something to crack inside? It was quite dusty when I blew it off. I didn't try turning on the machine until the morning after moving/cleaning the pump.

You may have a cracked wire. When I had my Linea I remember the wires were very brittle. Check the connections on the pump motor. I would also use a meter to check for power to the pump.

Mitch, turned out to be a loose ground wire on the motor. Luckily there was a piece of electrical tape separating the loose wire and metal base, otherwise there would of been some sparks when I initially plugged it back in. Thank you everyone for you input!