Ben fwiw it sounds like you have 2 problems. I had the same problem with a pstat and it only lasted 2 months. The next one worked fine. There should be a mfg date on the pstat. It seems like my first one was several years old and the second one was this year. I was having the same symptoms with the relief valve but no chatter. The chatter sounds like a relay or a solenoid. Can you pull the cover off and look at the relay while the chattering is going on? That might help narrow things down. You could have a bad pid or element in the brew boiler causing that not to get up to temp but honestly I don't work on these things enough to do anything but guess. I just bought the pid upgrade for my machine but I may hold off on installing it for a few more days. Maybe Todd will jump in and give you some ideas. Herman
On Fri, Nov 27, 2015 at 1:57 PM, Benjamin McCafferty <[email protected]> wrote: > Hey all! > Hope you all had a great thanksgiving and that you're all waking from your > food comas. I had more pie for breakfast, but alas, with no espresso. > > I will be talking to Todd soon about this, but thought I'd also ping the > collective and see if anyone has any ideas. Unfortunately, I have a > collection of symptoms at this point that I can't make fit a common cause; > perhaps they will make sense to one of you. > > As you may recall, I had quite a bit of trouble this summer, and during > that process I replaced: > > --Both hi-limit switches > --One or both boiler elements > --Giemme controller board with the updated one > --PID temp probe > --Main power switch > --New Jaeger pressure-stat > > Also, as with this summer's shenanigans, my mom is visiting in two weeks, > and dearly loves a good latte. I spent several hundred on overnight > charges, parts, etc. while she was here in the summer, and managed 2 days > of lattes for her in her three-week visit. Hoping to get the machine back > in action fast! > > At the same time I did all that work, I totally disassembled everything, > descaled completely, and cleaned the solenoid until it was shiny, i.e. all > scale removed, etc. The solenoid functioned fine with power. > > The machine worked normally from summer until this week, but with one > weird symptom. It would occasionally make a machine-gun noise, i.e. > something mechanical opening and closing very rapidly, 5-10 times per > second maybe. To me, it is a higher pitched sound than the solenoid, and > sounds like it originates from the area of the giemme controller. Todd > suspected the solenoid might be sticking; I was thinking perhaps one of the > two relays in the giemme controller was misfiring (not sure that they are > even relays--but I'm referring to the two small sets of contacts in the > giemme that look like points from a points-and-condensor ignition). At its > worst, this symptom would continue for 10+ seconds and I'd shut the machine > off and back on; it would seem to "reset" and stop. At its best, it would > last for a few seconds and stop on its own. It clearly is related to when > the machine goes to refill the steam boiler, i.e. when closing the steam > wand, dumping hot water boiler, etc. is when this would happen, very > intermittently. > > As of a week ago, the machine-gun thing got really bad, i.e. it happens > 4-5 times while steaming enough milk for a latte, etc. When shutting off > the steam wand, when it goes to refill, the machine-gun noise happens every > time and frequently does not stop. As the machine sits at idle and > occasionally refills the steam boiler, it also makes the noise every time. > > At this point, it would seem to me that the culprit would be the giemme or > the solenoid, but wait, there's more... > > A few other symptoms have happened in the past week, which really confuse > the issue for me, because I admittedly don't know exactly how electricity > flows through the machine: > > --The Jaeger P-stat has allowed the machine to over-pressure about 3 times > in 5 months, causing the blowoff to activate. No way this should be > happening with a new p-stat, but otherwise it has been normal. As an > aside, Chris Coffee will not warrant the p-stat, stating 30 days is the > warranty from that manufacturer. So I have a 90-day-old failing part that > won't be covered. Unexpected. > > --The PID display (which I have set to 204F) has stayed at 105F for > several hours each morning for about four days in a row, and then later in > the day, has heated to 204F. > > --As of two days ago, the PID heated the brew boiler to 105F and stayed > there all day, never heating to 204F. > > --Earlier this week, one day only, the PID display was blank when the > machine was on. It remained blank for about an hour, then suddenly lit > up. It showed 105F. Every time the steam boiler fired, the PID screen > would flicker and get really dim, almost not visible. Then it would > brighten right back up when the steam boiler turned off. > > --Most of the time (and this is an old thing, maybe normal), the PID > numbers and "dot" will blink every few seconds, i.e. they go off for a > split second, and then come back on. The dot at this point will not stay > on for more than a split second also, i.e. it never shows the boiler > calling for heat once the steam boiler is off. > > --The same day the PID display was blank and dim, there was a single time > where the steam boiler filled, and then shut off (solenoid clicked), but > the pump kept running indefinitely. I finally had to turn off the machine > to make it stop. After power cycling the machine, the pump filled and > stopped normally again. > > --At this time, the steam boiler fills and heats normally, with the > exception of the machine-gun noise, which happens almost every time. > > OK--I think that's it. I'm sorry if someone has told me this before, but > I'm trying to understand first how electricity travels in the machine. So > far, the only thing that seems like a common point to all of these symptoms > is the giemme controller, but that's based on my limited understanding. > > How I *think* it works is this: main power switch sends current to the > giemme, which sends current to the pump and to the pressure stat (via the > two "relays" in the giemme?). If the steam boiler is not up to temp, the > p-stat sends current to it until it is at pressure, then it sends current > onward to the PID. The PID sends that onwards in bursts via its > solid-state relay to heat the brew boiler. Meanwhile, the giemme sends > current to the pump (via a relay?) and to the solenoid, so the solenoid > closes, diverting water to the steam boiler, and the steam boiler fills. > When water touches the probe in the steam boiler, it essentially shorts out > and stops the pump, and the solenoid opens, sending water line pressure to > the brew boiler, which is held back by the group. When the lever is > lifted, the lever mechanically opens the group to let water through, and > the switch behind the lever sends power to the pump to cause it to run and > push water under pressure through the group. If, while pulling a shot, the > steam boiler level drops below its probe, the solenoid closes and > interrupts water to the brew boiler/group until the steam boiler is filled > again. > > Does that sound about right? Again, I would really like to understand > this whole circuit, especially the giemme controller and what the two > mechanical contacts are for on that board. > > --Also, my PID is about 5-6 years old by now; what is the expected service > life of those? > > --Can I safely test the PID by reversing NO/NC terminals on the P-stat? > Wouldn't that have the effect of prioritizing the PID first? > > OK, I'll stop. Enjoy your leftovers, and have a good coffee for me! > > best, > Ben McC > Sent from my apple IIe > > -- > You received this message because you are subscribed to the Google Groups > "Brewtus" group. > To unsubscribe from this group and stop receiving emails from it, send an > email to [email protected]. > To post to this group, send email to [email protected]. > Visit this group at http://groups.google.com/group/brewtus. > For more options, visit https://groups.google.com/d/optout. > -- You received this message because you are subscribed to the Google Groups "Brewtus" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. To post to this group, send email to [email protected]. Visit this group at http://groups.google.com/group/brewtus. For more options, visit https://groups.google.com/d/optout.
