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.
