I'm letting the machine warm up now and I will do a normal cooling flush and pull a shot and see what happens.

Okay, did cooling flush for around 12oz and let the temp settle at around 94 and pulled the shot. Post shot the temp is still dropping.

Did you pull the shot and followed your normal routine... clean portafilter, flush screen etc? Or did you just pull the shot, left the portafilter in and noticed the temp dropping?

It doesn't sound to me that your machine has an inherent thermosyphon stall problem as if it did, it wouldn't come up to temp before you pull the first shot. It sounds like you're inducing a stall by your routine. How long are you running the flush (in seconds) when you clean the screen after your shot? Try increasing the cleaning flush by say, 4 - 5 "additional" seconds.

Short flushes can cause a stall and it seems that's what you're seeing....

http://www.espressomyespresso.com/stall.html

I will do just that. I do short flushes post shot just enough to remove coffee from the group. I'll try a longer flush in the morning. I didn't realize short flushes could cause this.

Happy to say that after 2 shots this morning the group is maintaining its normal 98ºC hold. I am still doing the fan method, but after the shot I do about a 7 second flush and that is doing the job. Had no idea the short flushes could cause this. Thanks for the help.

Glad you got better results!

A short flush is just enough time to dump the water in the mushroom area, and since the pump isn't given enough time to refill the area before it got shut off, air gets trapped there instead of water. If your routine (time-wise) was anything like the video in the other thread you linked, then I can see why it happened. That other poster is also unwittingly inducing his own problem. The mushroom area doesn't really hold very much water, so no need to count seconds, just let the pump run, do your cleaning, clean the gasket area and shut the pump off and you'll have avoided a short flush.

It is normal for the group temp to drop post shot. On my Pro500PID HX, it drops steady for 3 minutes. The total drop is 5F.. then it starts to reheat. The Appartamento will also exhibit post-shot drop but it should reheat within 3-5 minutes.

I was once told that short flushes less than 1 second can introduce air into the TS and you could get a stall.. The fix is a long 10 second or so flush.. Maybe your cleaning flushes are too short. Try just wiping the screen and not doing a cleaning flush and note the behaviour. Ahh.. see you determined this.. my browser did not refresh and I did not see the previous posts.

Anyone know if having it on a smart plug could cause issues? I can't imagine it would but want to explore all options even though I'm pretty sure it was the short flushes. On another note, is it even necessary to flush to clean the screen or just wipe it?

My Andreja is on an old rotary type timer and I've had no problems with anything due to it. I'm unsure if a "smart" plug would do anything but I wouldn't imagine so. Once the machines on... it's on.

As for flushing the group... that's all up to you. Consider that when you pull a shot, coffee not only comes out of the portafilter, but also goes back into the group when you stop the shot. That "whoosh" you hear when you drop the lever is from pressure leaving the group. The rapid release also causes suction at the portafiler (little/short as that may be) and coffee is sucked up through the screen. This is why when you do backflushes in your normal cleaning routine, there's coffee residue coming out of the drain on release. If you don't mind plugging up your group screen and having to pull and clean it more often than you regularly do, then you don't need to flush. All up to you. I flush/brush/clean the group after every shot. Still doesn't stop coffee from passing through the screen though.

I figured as much. Is there any chance that I am pulling air into the system by way of the group head thermometer? I noticed a guy by the name of Howard Smith on YouTube pulling very short flushes as well and he does not appear to be having the same issue as I am.