Gaggia Factory aka La Pavoni Millennium water temperature...

[Kujako]

It seems to me that the brewing temperature on my Gaggia Factory isn't quite as high as it should be, the water I get out of it is hot, but not much hotter then I can get out of the water faucet (wont burn me).

Is there anything that can be done about this? This is the smaller eight cup unit and the cut off switch in the boiler would seem to be pressure based and beyond my control. I get more then adequate steam out of it, so I'm not sure what I could change. I could also be wrong and the water temperature is fine.

[A2chromepeacock]

Could you tell us a little more about your warm-up, flushing (if you do so) and shot-pulling routine?

Also, does the problem persist with subsequent shots?

Finally, how does the espresso taste?

[Kujako]

1) Turn on machine.
2) Wait for pressure light to go out.
3) Release trapped air with the steamer wand, which lowers the pressure and restarts the boiler.
4) Wait for the pressure light to go out again.
5) Attach empty portafilter and lift lever to allow water to flow through the system heating it.
6) Lower lever and wait for the pressure light to go out again.
7) Grind beans into filter, level, tamper and insert into portafilter.
8) Re-attach portafilter and position shot glass.
9) Lift lever and wait for first drops to dribble out.
10) Pull first shot, repeating step 9 for second.

Shot comes out dark with dark crema. Tastes a bit bitter, but that may very well be the beans I'm using more then anything else. My understanding is that hotter water results in darker creama, which would indicate that temperature is too high given the coloring, but that doesn't seem right based on actual temp'.

I'll take some readings with my infrared thermometer next time around.

[RapidCoffee]

It seems to me that the brewing temperature on my Gaggia Factory isn't quite as high as it should be, the water I get out of it is hot, but not much hotter then I can get out of the water faucet (wont burn me).

That sounds like much too low a temperature. When I raise the lever on my Gaggia Factory, the water flash boils as it exits the grouphead. It can burn the crap out of you.

Is there anything that can be done about this? This is the smaller eight cup unit and the cut off switch in the boiler would seem to be pressure based and beyond my control. I get more then adequate steam out of it, so I'm not sure what I could change. I could also be wrong and the water temperature is fine.

You should be able to adjust the pressurestat inside the base of the Gaggia Factory. Increasing the pressure also increases the temperature inside the boiler. However, I don't understand how the boiler water can be hot enough for adequate steaming, yet cool enough not to burn you as it exits the grouphead. It would be nice to see some actual temperature measurements, even if you just pulled a blank shot into a styrofoam cup with a thermometer.

[Kujako]

I don't understand it myself. As I said, plenty of steam and the outside of the boiler gets hot enough to sear the flesh off my finger. But when I do a test pull to heat the portafilter, it just doesn't seem like the waters that hot.

[r-gordon-7]

That sounds like much too low a temperature. When I raise the lever on my Gaggia Factory, the water flash boils as it exits the grouphead. It can burn the crap out of you.

That's exactly how it is on both of my two Gaggia Factories as well - with the water flash boiling as it exits the group head. Both of my two Gaggia Factories are the 16 cup model w/the gauge - and each of them seems to have arrived w/a very different pressurestat "factory" setting. The first one cycles off at approx 1 bar and back on again at approx .85 bar- and the second one cycles off at approx .75 bar and back on again at approx 0.5 bar. (Though I've been meaning to adjust the pressurestat to raise the setting on the one set lower - mostly just to increase that unit's milk steaming/frothing performance - I haven't gotten around to trying yet, due mostly to being put off by the special tool needed to take off the bottom of the unit, coupled with my understanding that the pressurestat setting is likely glued in place and would need to be broken free to be changed.) However, as the water flash boils as it exits the grouphead even on my Gaggia Factory with the lower setting, it would seem that if Kujako's doesn't, the pressurestat setting on Kujako's machine might be below 0.5.

r-gordon-7

[Kujako]

Main problem of course is that I have the smaller 8 cup unit without the handy gauge. So I just get on, and off with no readings in-between.

Ok, did some temp checking without a portafilter, just draining water directly into a double glazed glass.

First pull after releasing air pressure and letting the boiler shut off. ~150F
Second pull, where water steamed out rather then poured. ~175F
Difference in temperature can be attributed to heat loss due to the heating of the cold elements in the device. Which of course is why one does a "dry" pull to heat everything up.

My understanding is that a desired brewing temperature should be around 195 with an in-cup temperature of about 165. I would say its fair to guess that I lose about 20 degrees to the air as it hits the cup, so I may be spot on.

[Kujako]

Next time I feel like an espresso I'll check the temperature of the actual output.

[jamhat]

How long are you waiting from the time you turn the machine on until the time you pull the shot? Maybe you could give it a couple more minutes, which would raise the temp of the brew head and keep the water warmer as it passes through it. The brew head acts as a heat sink, cooling the boiling water before it reaches the portafilter. It seems that since you have plenty of steam, the water is boiling (212+ degrees).

Here's a link to a timed shot, posted by Fullsack: great-shot-europiccola-51mm-revised-t2548.html He's pulling a single, but the timing may still help you pull a double.

[Kujako]

Machine is on a good ten to fifteen minutes before I pull the first shot.

Espresso temperature is at about 145F, seems I'm losing a lot of heat to the portafilter & head despite warming it up.

[fergusstew]

Hi,

I had a problem with my Pavoni 16 lever not being hot enough, and so not having enough steam pressure. The solution was to clear the lime deposits from the thermostat. When I did that, the temperature and pressure shot back up.

The thermostat is in the base of the machine, and it's at the end of a blind tube coming from the base of the boiler. So even if you regularly boil up the machine with vinegar, the end of that blind tube doesn't really get cleaned, and it fills up with lime. When that happens, the thermostat isn't able to properly sense the temperature of water in the boiler.

You can fix this without opening the boiler. Remove the base of the machine, and separate the thermostat from the pipe that connects it to the boiler by undoing the plumbing connection. Disconnect the electrics from the thermostat and fill its sensor end with hot vinegar, then flush and refill a couple of times to get it really clean. Poke a long flexible object, like a pipe cleaner or cable tie, up the short bent pipe that connects the thermostat to the boiler, while dribbling some hot vinegar down the pipe. Reconnect the thermostat to the pipe and do 3 boil flushes of the machine with clean water.

You can see the tube in photo #36 of my Pavoni rebuild at http://cid-e0a4d8901828b395.space...A4D8901828B395!166

Hopefully this will get your machine back to making great coffee!

Fergus.

[Kujako]

Based on the amount of use this machine has had, I doubt its an issue with lime deposits. However, I cant actually check this or the pressure-stat till I get the right size bit to remove the safety bolt.

[Kujako]

Also thinking that going with a bottomless portafilter would help since keeping the brass hot for the pull seems rough. Course such things are a pain to get for these machines.

[Kujako]

No problem with deposits or any other visible issue with the guts of the unit, looks good as new. So I guess I'm up against trying to change the pressure-stat setting. (sigh)



Anyone have a good guide for doing so? Which bit gets twisted in which direction and how far?