Profitec Pro 800 temperature stability in V2

[poison]

The 800 was updated in 2022. I was just reading this thread, about 800 temp stability:

Scace thermofilter temperature measurements Profitec Pro 800

Has the new version made any changes to address temp stability, or does that thread's data still apply accurately to the new version?

[Moka 1 Cup]

This is the end of the third week with my new Profitec Pro 800.

I added a thermometer to the group head. I am measuring the temperature on the surface of the group, not internally, and the position of the probe was chosen for convenience more than anything else.

Here are two pictures of what I am using:





The boiler's temperature is currently set at 246F.
The screw that regulates the flow of the water to the group is one turn and a half from zero.

First of all, I have noticed that the group head takes longer that I anticipated to reach a stable temperature. Definitely more than 45 minutes. In order to get good consistent espresso, the measured temperature of the group needs to be above 175F. Ideal is above 178F.
This is not a big issue, if the boiler is already at the right temperature (it does not take long), with a couple of flushes, maybe three, I can raise the temperature of the group head in few minutes. I'll post a chart next time I do it.

Second, except for the first couple of days (probably due to "user's errors"), once the group head reaches 180F, the temperature remains quite stable. I have not seen the overheating reported by other members. There are fluctuations, for example after each shot, but the measured temperature goes back to stable values quite quickly. Typically it stays between 180F and 182F even if after one or two shots it may go up to 185F for few minutes, it goes back to that 180-182F range quite soon. I have not seen the temperature going higher than that even when I pull two, three or four shots in sequence.

Here is a chart that I put together with yesterday's afternoon temperatures.
All shots were made with a long preinfusion (until first drop).

[LObin]

Great stuff!

I don't believe there were any changes made to the V2 that could affect the thermodynamics of the Pro800 but in any case, it's good to know that the overheating problems may have only affected a few units.

On my Londinium L1 (not a dipper but an open thermosyphon) I had to install a flow restrictor in the hot tube to get the group to idle around 82C.

It didn't have the ball valve in the back of the group like the Pro800 does.

[Moka 1 Cup]

I forgot the mention that piece of information. I am going to add it now, the screw is turned open 1.5 turns from zero, if it makes any difference.

[Conch54]

As a pro 800 user I really appreciate the data I usually wait to use after 60 mins since it's timed to come on an hr before I get up and since I'm retired some times I give it a bit more warm up time lol thanks again
Luis

[Moka 1 Cup]

....
This is not a big issue, if the boiler is already at the right temperature (it does not take long), with a couple of flushes, maybe three, I can raise the temperature of the group head in few minutes. I'll post a chart next time I do it.
....

Here it is. I turned the machine on when the probe's temperature was at 86F. I had turned the machine off seven hours earlier.
Once the boiler got to temperature, I poured the water from the group four times, all times keeping the lever down just enough to allow water to flow, not at full pressure. It took 27 minutes and about 1 liter of water total, for the the probe to get back to 178F.

[Radio.YYZ]

Great to read you have done some good work there @Moka 1 Cup.

One thing i was wondering was the measurements of water at the grouphead is while water was passing through or just right when the piston was engaged (pulled down)? Or it was first engaged and then released, i.e. simulating a shot or while pulling a shot?

[Moka 1 Cup]

Thank you.
It's difficult to answer your question. Keep in mind that the temperature shown by the thermometer it's the temperature of the probe, which is attached to the surface of the grouphead. I have no idea of how the temperature changes inside the grouphead, but I assume that there is at least a delay.
Here is a video of the fourth shot that we made this morning. You will see that the temperature is 176F, than it raises to 178F during the preinfusion, it than fluctuates between 178F and 180F and it ends at 180F. After I stopped the video it went for a moment to 181F and then back to 178F (see the chart, the three previous shot were between 5:50 and 6:30).

[Radio.YYZ]

ahh i thought it was inside near the coffee cake/puck.

Outside temp wont change very much as you have shown, the inside measurements is where you will see a bit hump and somewhat of a declining profile throughout the shot.

What is your ambient temperature?

The flow control, any reason you adjusted that instead of leaving it at stock setting?

[JohnB.]

You'd get a more accurate temp reading if your probe was against the lower group just above the bell. Measured there I see an idle temp of 171-172°F after the machine (Bosco Sorrento) is fully up to temp (1.5 hours). Did you do a corrected calibration with your temp probe/meter.