Good morning, Home Baristas!

I've been working on a Quick Mill Monza (model #5010) for a couple weeks now and have not been able to figure out what the "Group Error" alert that pops up on the display means. Wondering if anyone here has experience with this machine and/or can tell me what that error is referring to?

I purchased the machine in a non-operational condition and, with the help of the good folks on this site, gotten it to power on and have thoroughly cleaned and lubricated it. Motor runs and pistons now move freely in and out of the brew group a couple times and then - click - everything stops, red display and error message.

I just can't figure out this error message and can't get any info via what seems like a million Google search attempts. Anyone have any ideas?

Thanks in advance!

The reed switches aren't seeing the magnets? It would explain why it doesn't stop trying to position itself and eventually gives up. Replace the reed switches?

Ah! Thank you. Yep, that would make sense.
I'll open it back up and pluck those sensors out.

Then to the interwebs to order a replacement!

Thanks for the thought!

When working correctly, the Monza will always move both pistons all the way down and then all the way back up through a complete cycle of travel. This is normal. Since the piston is moving up and down properly through it's entire range, that means that the piston is working well. In such a case, the group error is actually indicating that either the temp sensor or the heating element for the group is faulty. Since the error is popping up right away, this tells us that it is more likely an open connection somewhere, rather than a bad sensor. (If the issue was the sensor telling a fixed resistance/temperature or the element not heating the group, then the error wouldn't pop up for 2-3minutes at the earliest)

I'll open it back up and pluck those sensors out.

I have to highly recommend against this. The two magnetic sensors inside the machine are looking for the magnet on a timing wheel in the gear assembly internal to the machine. It is finicky to get to, and even more so to put it back together properly afterwards. The piston assembly in this machine does not have two way travel, it has a motor spins in only one direction, and it relies on half gears connected to the upper and lower pistons to time that movement. Put the gears back together wrong and you can make the pistons move out of time with one another, and jam the entire assembly. It is tedious to move the motor backwards once it's been jammed, so I recommend avoiding the headache.

We know that the piston is working properly, so there is no need to make problems for yourself where none exist.

I recommend starting by checking to see if the hi-limit/fuse for the group is good, and then checking to see if the connections on the board are secure. I put two photos below which show the location of these parts.

GreenEggsAndSam wrote: I have to highly recommend against this. The two magnetic sensors inside the machine are looking for the magnet on a timing wheel in the gear assembly internal to the machine.

Thank you, Sam.

Dennis, please trust Sam's input over mine... WAY over mine.

Incredible! Thank you both for taking the time to chime in. Really appreciate it!

Sam, you were absolutely correct! Thank you so much. There was indeed a connection on the board that had come loose. I hate to admit it, but it was probably all my fiddling with the machine in the first place that knocked it loose. Dangit.

Error code is gone and, while the tube that brings water into the top piston keeps popping out mid-brew, the rest of the mechanics seem to be working as intended.

I'm amazed at all the knowledge here! You've helped me take a shiny but lifeless box and turn it into an almost working espresso machine.

Can't thank both of you enough.
Sam, you are the man!

I hate to admit it, but it was probably all my fiddling with the machine in the first place that knocked it loose. Dangit.

Glad to hear you're up and going again! And don't worry, it happens to everyone. I can't even tell you how many times I've done that.

Error code is gone and, while the tube that brings water into the top piston keeps popping out mid-brew,

There are a few things that can cause that tube to pop out:
-Sometimes the crimped brass piece on the teflon tube comes loose over time, can you check to make sure it is still firmly attached to the tubing?
-The tube should have two o-rings at the end of the tube. If there is only one, it can work loose over time through use. Check to make sure both are there (and lubricate them with DOW111 if you haven't already, they benefit from being kept lubricated)
-The crimped brass piece should go into the piston head, then a collar should go down the shaft of the piston, where it overlaps the crimped piece. This is what provides the majority of the holding force which keeps the tube in place. The collar is then held by a cotter pin that is set above the collar and goes through the shaft, to keep the collar from moving up the shaft and allowing the tube to come loose.

Let me know if I'm not describing that well, or if you'd like some photos of another Monza piston head to compare to.

Thanks for that info, Sam!

I haven't had a moment to dig back into the machine yet, but I'm thinking about the piston and tube as I was putting everything back together after cleaning, etc. Two pieces you mention stand out - first, I believe there was only 1 o-ring at the end of the tube, and I did not lubricate it. And second, I remember feeling like the collar that goes over the piston was not fitting perfectly and I had to force it a bit to get the cotter pin in place. Maybe it wasn't holding the tube in place because I didn't attach it properly.

I'm going to get in there ASAP to check these things out!

Thanks again, Sam! You are a wealth of knowledge and very generous with it.
I'll let you know how things pan out.

I know this is a very old post, but I'm so grateful for the help I received from the folks on this site that I wanted to provide an update.

After going through everything that was recommended, I brought the Monza from dead as doornail to running and working enough to almost pull a shot. So close!

I did end up bringing it in to a wonderful local technician who cleaned the boiler and water sensor, and dialed in my grind settings. And now, with a little help from my friends here on home-barista and a few hard earned dollars out of my pocket, we are enjoying some pretty darn wonderful coffee drinks at least once a day!

Thank you so much!