Hi all-
Just bought a used non-functioning 2002 BZ02S from a friend for $100. Hoped l could get it working with minimal expense. Friend claims that it was working fine until he had to replace the plastic slipout water tank in the back because it cracked...then the machine stopped working. Tank seems correctly placed and contact wire is connected. The symptoms are these...
Machine turns on normally with the green power light on and the small green and orange lights on. Boiler heats up and can produce steam from steam wand, produce hot water from hot water wand and pull shots from grouphead as well. After about 20 minutes and click is heard and the small green and orange lights on the machine go out and the pull shot button, steam and hot water controls all stop functioning. But the green power light stays on and the boiler seems to stay hot.
Any help would be greatly appreciated.

The Bezzera listing of their machines (go to the page showing their "semiprofessional" machines) includes PDF downloads of the parts darawings and lists (Kudos!).

I'm guessing the immediate problem is the thermal cutoff underneath the boiler; but you'll need to troubleshoot the machine to confirm this, and to find out why it's tripping. This is something the buyers of 2nd hand machines should be prepared to do.

Hi Jim
Thanks for your super prompt reply.
Can i bypass the thermal switch temporarily to see if this is the problem?
Rob

chamlight wrote:Hi Jim
Thanks for your super prompt reply.
Can i bypass the thermal switch temporarily to see if this is the problem?
Rob

While you likely can, this may be pointing to a problem with a pressure-stat failing to open with age/scale/etc. Relatively inexpensive to fix. Do you see the power to the boiler cycling on/off? I don't know if this machine has a indicator of the boiler being turned on, but you can likely hear it cycle on/off. Failure of this part would allow a machine to heat up and then to keep going until either the p-stat worked or an emergency over heat circuit kicks in.

Be really sure there is enough water in the boiler, or you could also risk burning out the heating element.

Mark

You can BUT I wouldn't as that is asking for trouble.

When I look at their parts breakdown, it shows two water level probes extending into the boiler with a difference in length of 50 mm (~2 inches). I SUSPECT that when the longer probe is uncovered (low water level in the boiler) the machine shuts down via some relay in the control box.

Maybe its time to remove some handy fitting on the boiler top and verify that the water level is correct - say about 2/3 full.

Mark and Eric thanks you both so much for replying.
Mark, the pstat seems to work as when I rotate the small screw left or right, the element turns on and off. Also I bypassed the pstat as well and still the machine shuts down after a period of time.

Eric, I bypassed the thermal cutoff on the bottom of the boiler (as you smartly suggested I NOT do) and still get the same result. I have now put both the pressure and thermal cutoffs back on (see I'm not that crazy:) ). I did notice as i was working that it is the "Finder" brand power relay that trips. I am intrigued by your suggestion about the water level probes and will check to see what condition they are in and what the water level in the boiler is. Could the power relay have gone bad?

Could the power relay have gone bad?

I would think that the Finder relay is controlled by the pstat. Tracing the wires would answer that one. Check the water level with a small wooden dowel - machine cold & unplugged.

What kind of water are you using to fill it? Don't use pure water (distilled or RO water) as there won't be enough minerals in it for the water sensor to figure it out.

Mark

Mark-
I'm using good 'ole NYC tap water

Eric-
Water level is about 2/3 full. And to test the minimum water level probe, I disconnected it and the machine shuts down I think as it should...although it shuts down in the same manner that it has been doing after it has been on for a while. Also to test the other probe which is the shorter fill level, I disconnected it and the pump started to fill the boiler...so that seems to work as well. Also I removes the probes and cleaned them...they werent that scaly.
When I run the hot water, it comes out at about 180 deg F with a fair amount of steam...does that seem right? I'm not sure where the thermostat for the boiler is...could that be the problem or maybe the "Giemme" water level regulator (which seems to be the brain/pobably most expensive part)?
Thanks
Rob

PS Machine has been on for an hour...went to run the hot water and it shut down...ugh

Water level is about 2/3 full.

Sounds very reasonable to me.

I disconnected it and the machine shuts down I think as it should...although it shuts down in the same manner that it has been doing after it has been on for a while.

That's a pretty important data point. With the machine in normal operation, move/wiggle this particular wire at both ends - "searching" for a poor connection point. That wire should go from the probe directly to the "black box".