*that is the brilliance (LOL) of the design.*
*and why WLL has dropped EXPOBAR* On Tuesday, September 7, 2021 at 6:38:42 AM UTC-7 billherbst wrote: > > Thanks so much, Brian. That's about as exhaustive an informed diagnosis as > I can imagine. > > Your comment about plumbing problems being permanent while electronic > failures are often intermittent might be relevant. The very first time the > problem occurred (hissing and steam during group head water flow), I was > pulling a shot. I noticed that something was wrong with the pull — the cone > on the naked portafilter was foamy, spurting, and more voluminous than > normal. That's when I heard the hissing and saw the steam. During the shot, > the PID showed 200°. When I lowered the group lever, however, the PID > display suddenly shot up to 220°. In a panic, I turned off the machine to > let it cool down. Through the subsequent times the problem occurred over > the next day or so, the display never again read 220°, but that was one > reason I thought the PID might have failed, as I asked in my initial post. > > If the problem recurs, I'll remove the case and check the controller > wiring for corrosion or loose connections. I'll also try your suggestion to > purge a cup or two of water from the steam boiler through the hot water tap > to lower the steam boiler water temp after it refills but before reheating. > If that lowers the brew water temp and stops the hiss/steam, it should > indicate if the problem is plumbing related, probably through back flow > from the fill valve. > > I appreciate your common sense statement that the high internal temp of > the Brewtus is hard on electronics. Historically, I'd always turned off my > old Brewtus II and more recent IV-r after making an espresso. Over the past > year, I've been drinking 3-4 cappuccinos throughout the day, so I'd been > leaving both boilers turned on 24/7. Whether because of profligate energy > use or wear and tear from internal heat, that probably wasn't wise. At this > point, I turn off the steam boiler after each use. Seems prudent. > > > On Monday, September 6, 2021 at 10:41:48 PM UTC-5 Brian wrote: > >> Hey Bill, >> >> Glad the problem went away but heres a few thoughts to help should it >> return. >> >> The two boilers are only connected at the fill, and the solenoid is >> supposed to prevent any flow between when neither is filling. Should this >> fail open it would be possible for water from the steam boiler to enter the >> brew boiler. Additionally there is a copper preheating tube as part of the >> brew boiler fill pathway that runs through the steam boiler. If that tube >> or the fittings were to fail it is possible for water, or worse steam, to >> flow into the brew boiler. Descaling is done with acids that breakdown >> mineral deposits, and also break down copper and brass. The reason copper >> and brass look so damn shiny after a strong acid soak is because the outer >> corroded portion of the metal has been chemically stripped, exposing fresh >> metal underneath. It's certainly possible with a strong enough acid, and a >> long enough contact time that the copper tube that passes through the >> boiler may have become weakened and failed, though I admit that seems >> unlikely. >> >> That said I do not believe either of those is probably the cause. With a >> rotary machine, and especially if it is plumbed, my intuition says that it >> is pretty unlikely that the relatively low amount of pressure in the brew >> boiler would be able to over come the pump pressure. Additionally any water >> entering the brew boiler would assumedly mix with the relatively large >> volume of water making it unlikely to get to the grouphead without blending >> some. And if it was heating the temperature of the brew boiler then the >> temperature controller should show that the boiler is over temp before you >> send water to the brewhead. I assume if this was happening you would have >> mentioned it. >> >> What seems far more likely to me is that the extra heat inside the case >> from having both boilers on is causing the temp reading that the controller >> is seeing to appear low so it overheats the water. I would check from >> corrosion or loose connections to all the wires on the temperature >> controller. It could also be a bad controller or a bad probe. These >> electronics do not do great over the long term with how hot the inside of >> the brewtus gets. Additionally plumbing problems tend to be permanent, >> while electronics issues can often be intermittent. >> >> One thing to keep in mind, the temp display on the temp controller >> actually has an offset of between 10-18 degrees F. This is because the >> controller is measuring the temperature of the water at the boiler, but >> what we care about when making espresso is the temperature at the >> grouphead. The water by the time it reaches the grouphead tends to be about >> 10-18 degrees F cooler than at the boiler. So at a setpoint of 200, the >> water in the brew boiler should actually be about 210-218. Just something >> to remember as you go about troubleshoting. >> >> Best of luck, >> -Brian >> >> On Sunday, September 5, 2021 at 9:45:23 PM UTC-4 billherbst wrote: >> >>> >>> UPDATE: It's now been a full day since my first troubleshooting >>> experiment (turning off the steam boiler). Oddly enough, everything is >>> working properly, even with the steam boiler turned on and at full >>> pressure/heat (1.3 bars). No hissing or major steam through the group head >>> as happened before. When I activate the pump by raising the group lever, >>> there's a typical 1-2 second delay before water flows with the tiniest wisp >>> of steam at first (presumably because the group head is hot), but the water >>> temp is right at the 200° F PID setting and remains there for as long as >>> the pump runs. Pulling shots is completely normal. I'm relieved but >>> cautious. I don't know what caused the problem, nor why it's now stopped >>> happening. >>> >>> I did find a workaround in case I need to turn off the steam boiler. >>> Pull a shot, pour 6 ounces of moo juice or cashew milk into a pitcher, add >>> some coconut oil, then whip/froth that concoction with a stick blender. Add >>> it to my long-pull espresso shot (4 ounces), then nuke it all in the >>> microwave for 30 seconds. Voilá! A nice foamy latte. A bit inelegant >>> perhaps, but quite tasty. Happily, though, I'm back in business — at least >>> for the moment — with normal milk steaming on the Brewtus. >>> >>> I'm still interested to know why/how 220° water from the steam boiler >>> was coming through the group head. Should anyone here have any insights, >>> I'm all ears. >>> On Saturday, September 4, 2021 at 2:25:54 PM UTC-5 billherbst wrote: >>> >>>> First troubleshooting experiment (to try to rule out possible causes of >>>> the problem): This morning I turned on the Brewtus IV-r (after a night >>>> where the machine was turned off), but I did NOT switch on the steam >>>> boiler. I left it turned off, so that only the brew boiler would heat. >>>> >>>> Interesting results. The Brewtus heated up the brew boiler and reached >>>> the PID set temp of 199° F in about ten minutes. I removed the naked >>>> portafilter and lifted the group lever to see what would happen. Brew >>>> water >>>> streamed through the group head exactly as it should and appeared to be >>>> the >>>> correct temperature (no hissing or steam). I pulled a shot, and everything >>>> was fine. >>>> >>>> I left the machine turned on and went back an hour later to check >>>> again. Still good — brew water flowing through the group head was the >>>> correct temp with no hissing or steam. To the best of my ability to apply >>>> logic, this implies that the problem isn’t with the PID at all, and is >>>> instead somehow tied to the steam boiler and internal plumbing. >>>> >>>> The problem I had six months ago was caused by scale. The water in my >>>> town is so hard that scale build-up had caused the solenoid-operated valve >>>> (the one that's normally closed but opens when the steam boiler level >>>> sensor triggers refilling) to seize in the open position. Replacing that >>>> valve and de-scaling the machine fixed the problem, and I resolved to do a >>>> citric acid de-scale at least once a year. >>>> >>>> Now it’s six months later, and I’m wondering if scale build-up has >>>> caused a problem with the internal valves that control direction and flow >>>> of water from each boiler. I still don’t understand why and how 220° water >>>> from the steam boiler can be coming through the group head, but it is. >>>> Perhaps someone here knows and can explain that to me. >>>> >>>> On Saturday, September 4, 2021 at 4:16:23 AM UTC-5 billherbst wrote: >>>> >>>>> Well, there’s more trouble with my Brewtus IV-r. Judged by gauges, >>>>> lights, and valves, everything is normal and operating as it should, but >>>>> when I raise the e-61 group lever to activate the brew cycle, the water >>>>> that comes through is way, way too hot. Yes, a stream of water is pumped >>>>> through the group head, but it’s accompanied by loud hissing and a large >>>>> volume of steam. >>>>> >>>>> The PID is set to 199° F, but the water coming through the group head >>>>> is hotter than boiling — 220-230°. >>>>> >>>>> Has the PID failed? Has anyone else had this problem? >>>>> >>>> -- 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 view this discussion on the web visit https://groups.google.com/d/msgid/brewtus/cd868196-a2e1-4045-aecf-704b2305c55dn%40googlegroups.com.
