Bezzera BZ07 sometimes heats up and builds steam pressure, sometimes not

Equipment doesn't work? Troubleshooting? If you're handy, members can help.

#1: Post by YvesMcQueen »

Hey community,

I have a weird issue with my bezzera bz07.

It served me very well so far but since short I have two issues with it and therefor two questions I hope someone can give me the answers too.

Problem number one;

It started after I had the machine on for a longer time; everything was working well and suddenly it didn't build up pressure anymore. I do get water (warm from the group head but none through the milk steamer or tea water) but the pid is indicating that it is not heating up proper anymore. If I let the machine cool down completely I can start it up again. Most of the time it will work for 30 min and then again looses all pressure....
It's very random sometimes no issue sometimes it doesn't work at all.

The second issue I have is with the pid and it might me related. It gives me option which don't make sense I can choose between 116 and 124 degrees. Which doesn't make sense in either C or F. I can not find any info regarding this issue. Is there a manual regarding the pid of this machine.

With friendly greetings; I really hope someone can help me out or direct me the right direction. I am not afraid of opening the machine. I am quite handy and have basic electronic knowledge.


#2: Post by JRising »

It's in Celsius. Reasonable temperature range for your boiler. The BZ07 is a heat exchanger machine, the PID would be controlling the boiler temperature, the water flowing through the heat exchanger is heated by that boiler, so long as it's not allowed to idle too long, it won't rise above boiling temp. If it is allowed to go above boiling, the heat exchanger can be flushed and brought back to brewing temperature by just running water through until the steam turns back to liquid.

But that doesn't answer the "Sometimes not heating" issue. To figure that out you'll need to see if the powerboard is energizing the resistenza connection even when it's not heating. And if it is, then see where the power is interrupted. To me it sounds like the powerboard overheats after being on for some time and shuts down, either the board if the transformer shuts down, or just the relay for resistenza if the relay is carboned up and burning away.