RobertRo101 If I’m reading it right, you normally didn’t have the portafilter locked in, but only locked it in before making a coffee. This time when it worked OK, you had left the portafilter locked in?
If this is the case, yes, it could well make a difference…
Let me try and explain a bit better. In the first weeks since I got the machine, I did not always leave the portafilter locked in, most of the time I didn’t, but the temperature was always constant and in the “right” range of 91.5-92. But since last week or so, something happened the machine started going crazy (and driving me crazy as well:) ) and I presumed that it stuck itself in HX mode (I am yet to do the test @MediumRoastSteam recommend above that I do), but this morning I left the portafilter locked in and immediately, 2-3 minutes, saw the temperature drop from 93.5-94 reading in idle to 91.5-91.8 (which is the temp I had before all of this craziness) and out of curiosity I made a coffee and the temperature during the extraction was very constant and in the normal range, exactly like it was before.
But I can not wrap my head around what could possibly change the whole system in idle and during the extraction by just simply leaving the portafilter locked for 2-3 minutes.
Just did another test. I let the machine cool off and then started it again, with the portafilter locked in I went a few minutes ago to check on it, after around 50-60 minutes of warmup, the thermometer read 92.3 in idle and as soon as I removed the portafilter, the temperature started increasing to 93.8. Manometer steam pressure was again around 0.5 bar.
Could it be that the portafilter actually catches the surplus of high temperature that I have been seeing in the past week? And if so, what could cause such an increase and what could fix it?
RobertRo101 Just did another test. I let the machine cool off and then started it again, with the portafilter locked in I went a few minutes ago to check on it, after around 50-60 minutes of warmup, the thermometer read 92.3 in idle and as soon as I removed the portafilter, the temperature started increasing to 93.8. Manometer steam pressure was again around 0.5 bar.
Could it be that the portafilter actually catches the surplus of high temperature that I have been seeing in the past week? And if so, what could cause such an increase and what could fix it?
I am not a physicist, just an owner like you, so take what I say with a grain of salt: First, My portafilter is always in the machine (accept for when I knock out the puck and wash it, of course). I don’t lock it, just “store” it in the group in a way that it stays there and doesn’t push against the gasket. This way, when the group heats, the PF heats with it and is a part of the thermal mass of the group. When you make a shot everything is nice and hot, and you don’t confuse things with different temperatures of the group and the PF.
Common sense tells me the above is how the machine was designed to be used. If you think about it, the group and PF are like a large heat sink. They absorb heat from the water and lose heat to the surrounding air. The software uses the temperature of the water to calculate how to control the heating element to turn on and off so that the end result will be the set temperature in the group. So if you add/remove metal mass from the machine, or if part of the mass (the PF) is at a colder temperature because it wasn’t in the group, this can cause a change in the temperature of the water in the thermosyphon and confuse the software, resulting in the fluctuations you see in group temperature.
I don’t have a group thermometer so can’t confirm this, but you do, so it should be very easy to see if keeping the PF in the group stabilises the temperature or not. If it does, then your problem is solved.
Well, after a few tests, this is what I will do going forward: leave the machine to warm up without portafilter, and 4-5 minutes before making a shot I will lock in the portafilter to reduce the idle temperature to around 91-91.5 and more importantly the extraction temperature to around 92 (+-0.5), this is all in temperature setting 0.
Another option is to find a position (not too tight, not too loose) for the portafilter to be locked in the grouphead.
Strange thing is, I did not have any problems like this in the first weeks of use so something happened inside the machine but at least I am glad I could find a “fix” for it. Will come back with updates and readings from the thermometer after a few more tests.
Who knows, maybe it will help somebody that has problems with the stability and doesn’t have a thermometer and has the V2 of the Mara (as Lelit said when I spoke with them, the V2 has a new more “aggressive” software to get the machine warmer faster and I am guessing they do this by overheating it after start-up).
Well, yeah, but it seems to be reliable and the only way to get the temperature to normal again.
On another note, the machine has now been warming up from a cold start for about an hour on the “steam mode” or the 0 position on the switch and at temperature setting 2 and the manometer for the steam pressure reads around 0.75 bar. I checked the manual and it should be, according to the manual, between 1.3-1.6 bar.
No, it doesn’t, but I don’t use the steam mode, it’s just a test I did. But to be honest I am a bit afraid that the problem could be with something that may affect the machine long term and cause some real damage.
RobertRo101 this is what I will do going forward: leave the machine to warm up without portafilter,
Not sure about the rest, but is there a specific reason for you to insist on warming up the machine without the portafilter in the group?
I am not insisting to do that. I don’t actually want to have to do that. But this way, after the warm-up I can insert the cold portafilter for 2-3 minutes and drop the group temp a bit and also the brew temp, and it seems, at least on the thermometer reading, that the temp is more stable this way. I did another test from a cold star-up with the pf locked in and it still was a bit too hot, 92.5 was the reading and the extraction was around 93-93.5.
If I am reading this thread right you have only had this machine for a short time? If so, and you are unable to reach satisfaction with the workflow or the machine, I would return it and get something else. I would not want to put up with that. Very frustrating for you. I am hopeful this gets resolved, because this is supposed to be fun and satisfying. Temperature stability is important. I have an Elizabeth, and it is rock solid. Keep us posted, but I would have a low threshold for returning it if you are not satisfied. There are so many good machines.
RobertRo101 - in all honesty… short of thinking the PF can act as a heat sink,I don’t understand how the relative low mass of brass is influencing thermal stability in such way.
I don’t know either, I can make a video for you guys to show what I mean, but I just made a coffee and I will let the machine a little time, around 20 min, to stabilize.
@dndrich unfortunately, it has just passed the 30 day return period, I think it turns 6 weeks on Monday:))
In all seriousness, I was very very satisfied with the machine and the temperature stability and range first, coming from a 41TEM it was amazing, but something happened, and from a smart Mara it turned into a much dumber Mara in the past week.
RobertRo101 - don’t you have a 1 year guarantee against defects?
I have warranty, I have spoken with the retailer, but they had to speak to Lelit in Italy because they did not know what was wrong from what I described to them. A guy from there told me that “a 2-3 degree difference is not that bad”:). But I was referring to the return period.
RobertRo101 Well, depending on where you bought it, perhaps they will make an exception. That assumes you might want to return it. If you bought a slightly more expensive machine, that might make it palatable for them. Just a thought. If you are going that route, then you might want to get on it this week.
Well, that’s the second call of tomorrow’s morning. Thing is, I don’t really want to replace it, it grew on me and this setback is not that bad if it is fixed. I was enjoying it a lot while it was running normally. And with this budget, which was already stretched enough:) I could only opt for a high-end single boiler like ECM Classika PID, but I am yet to find good tests for its temperature stability or the Minima, but that would have to wait a few months to get by budget in range.
RobertRo101 Yep I understand. You might consider the Elizabeth. Just a bit more money. Doesn’t have that sexy curb appeal, but you cannot beat the performance for the price. Mine has been amazing.
This video should explain it a bit better:
(sorry if shaky, I just realized that 4k60fps doesn’t have movement stabilization)
Essentially, after inserting the portafilter, the temperature will drop and stay between 91.4-91.8 and stay there, add 0.5 degrees to that number, and that is the average temp during the first extraction. This temp will eventually increase if the portafilter is left there long enough (IDK how long exactly, I observed this phenomenon after a cold start with the pf locked since the begging), to around 92.5-93, again, add 0.5 to that to get the average stable brewing temp.
As I said above, the temp I get without the portafilter is 93-94, after adding 0.5, the average temp, in this case, is 93.5-94.5 during brewing, which is very high for the lowest setting and was not the case with the machine in the first weeks of use, and it fluctuates much much more than the extractions using the processes described above, which are very stable.
