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Novice needing information on HX group water temperature...

Postby drumhead954 on Sun Jan 16, 2011 3:54 pm

After "rebuilding" (essentially a cleanup, as it was still in great shape other than having had water sit in the boiler for almost 8 years) my 1996 Astoria Laurentis Junior (single group), 2000 Watt, HX machine, the water temp still seems to be considerably below where it should be. The boiler pressure shows (new gauge) between 1.2 & 1.5 bar (I've adjusted the Sirai pressurestat up somewhat), but a candy thermometer directly under the brew head shows between 170 & 190 degrees. The temps seem to vary considerably. Even the water from the water dispenser is only about 205-210 at the hottest, when brewing into a small heated container. The steam wand does perfect steam.

Can the boiler pressure be correct & the HX water temp not be where it should be? I've read a good bit on the pre-extraction flush to get the temp DOWN, and that pressurized boiler water can reach temps of 235-250, so I obviously have a problem.

It doing my cleanup, I took the group head "apart" and my visual inspection showed almost zero calcification. I did not open the bolt on the top of the group as I didn't know if parts would come flying out or what. Is it possible that I have problems there?

Any info/advice is much appreciated!
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Postby HB on Sun Jan 16, 2011 4:45 pm

drumhead954 wrote:...a candy thermometer directly under the brew head shows between 170 & 190 degrees.

That's not very accurate. Try the foam cup technique documented in Seeking low tech way to measure brew temperature.

drumhead954 wrote:I've read a good bit on the pre-extraction flush to get the temp DOWN, and that pressurized boiler water can reach temps of 235-250, so I obviously have a problem.

Actually that's only half correct; as documented in HX Love, the flush equalizes the group temperature. That is, the HX is cooled, the grouphead is warmed, and hopefully all works out in the end.

I could be wrong, but nothing you've written so far indicates a problem with your espresso machine. If you want to post a video of the flush, I'll be happy to provide my best guess at the end-of-flash and a starting point for pulling the shot.
Dan Kehn
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