Elektra A3/T1 brew temperature too high after long idle period

by **Fullsack** on Sun Nov 22, 2009 12:58 pm

cannonfodder wrote:...My home machine gets one or two shots in the morning, one or two shots in the evening...

I don't know, if the "Cannonfodder" A3 gets turned off in between morning and evening. When my T1 is left idle for several hours it overheats and the evening shot isn't as good as the morning shot, even when the Elektra recommended cooling procedure is performed, (flush through the water wand 5 times for 10 seconds and flush 1 liter of water through the group).

Maybe there is a better way to cool an overheated A3/T1, rather than having to turn it off and then wait for it to reheat later in the day, but I haven't figured it out. One of the reasons I purchased a commercial machine was so I wouldn't have to turn it off.

by HB on Sun Nov 22, 2009 1:08 pm

Here's what I did during the evaluation for the Buyer's Guide to the Elektra A3:

HB wrote:My first approach prior to the arrival of the thermofilter was a variation of the technique I applied for rousing commercial machines with heavy groups to simulate an extraction: Flush... wait... flush... wait... flush... pull shot. It helped the first shot, but the second and third were always better. Let's try it another way, and this time I won't have to waste a lot of coffee. My theory was that I could nail the temperature more accurately for the first shot by overcompensating slightly for the first flush. In other words, instead of counting off a cooling flush of "one Mississippi, two Mississippi... six Mississippi", add a couple extra seconds to warm the group up (just a tad more) and cool the heat exchanger (just a tad more). I measured the resulting brew temperature for each of the three first "shots" into the thermofilter, adjusting the first flush by small increments. I learned some tricks that let you zero on the right temperature from the get-go and reach a new level of heat exchanger temperature consistency:

Flushing for a few extra seconds the first time to compensate helps the first shot. For this machine, add three Mississippis past the end of the water dance if it is "really really" idle for a total of approximately nine seconds.
If you have the extra time and want more accurate temperature brew temperature for the very first shot, wait an additional two minutes, repeat a normal flush as shown in the video from Pulling Shots by the Numbers, wait an additional two minutes, then repeat the normal flush followed by the extraction (that is, "longer flush... wait... normal flush... wait... normal flush... extract" brings the group to temperature as if you pulled two shots)
Pay attention to excessive "rinse" flushes. I have the habit of running water through the group to clear the dispersion screen. If the next shot is pulled soon thereafter, it affects the next shot's flush time. I know, I know... duh. Now if I'm pulling successive shots, I hold my OCD tendencies at bay and let the cooling flush handle the rinsing.
These small changes have increased my temperature consistency, so much so that Geoff remarked that it was a non-issue in our shootout. That's high praise considering the capabilities of his gear.

by **zin1953** on Sun Nov 22, 2009 2:29 pm

Doug,

I have my machine on a timer. It's set to turn the machine on at 5:00 am, and off at 9:00; on again at 5:00 pm; off at 9:00. It's a mechanical INTERMATIC timer, and I have taken off the 9am "OFF" pin. IF I am going into work the office (which I'm lucky enough not to have to do every day), I now turn off my machine manually, and it will turn back on before I come home. However, if I'm staying at home, it remains on from 5:00 am-9:00 pm.

I don't count the "Mississippis" as Dan suggests, but I do (approximately) double my flush routine if it's been idle for a several hours.

Cheers,
Jason

by **cannonfodder** on Mon Nov 23, 2009 12:18 am

She runs 24/7. I have also turned down my pressure to lower the temperature. I run around 1 bar, maybe just a touch higher. Machine has been in storage for 3 or so months. I do not do any boiler purges before a shot but I do, do a few flushes. The first being quite long, probably 8 ounces. Then I get my cup, milk, etc... ready, pull another flush, pull the portafilter and do my grind/dose, pull my pre shot flush and pull the shot. Works good for me. I have also insulated the boiler.

by **Fullsack** on Thu Dec 03, 2009 10:57 pm

Using Dave's 8 oz. flush plus a couple of short flushes does the trick. For cooler shots, Dan's "Mississippis" after the water dance is a winner. What didn't work was the Elektra recommended approach. Elektra should consult Dan and Dave before their next instruction manual update.

by **cannonfodder** on Fri Dec 04, 2009 12:12 am

8oz is just a guess but it is in that ballpark, maybe a little more. I just know when I am there. The first flush is blasting hot, blows water everywhere. It is intended to flush a lot of water through the HX and group to cool it, the remaining flushes are simply to keep it from getting to hot again. If you are pulling multiple shots after that first flush, it is simply a cooling flush before each subsequent shot. A long cooling flush is no longer needed unless you let it sit for another hour.

by **Fullsack** on Tue Mar 16, 2010 9:58 pm

HB wrote:HB wrote:Flushing for a few extra seconds the first time to compensate helps the first shot. For this machine, add three Mississippis past the end of the water dance if it is "really really" idle for a total of approximately nine seconds.
If you have the extra time and want more accurate temperature brew temperature for the very first shot, wait an additional two minutes, repeat a normal flush as shown in the video from Pulling Shots by the Numbers, wait an additional two minutes, then repeat the normal flush followed by the extraction (that is, "longer flush... wait... normal flush... wait... normal flush... extract" brings the group to temperature as if you pulled two shots)

Dan,
I'm having a little problem getting the stable temps you get in the video, (my temps keep dropping during 40 seconds, the total Scace time from the video), and am confused by the "longer flush..." of nine seconds and normal flush from the video which I time at 11 seconds. Earlier in the Buyers Guide, you mention a water dance of five seconds and additional drawing time of 6 seconds, again equaling 11 seconds. By normal flush, do you mean just the water dance of 5 seconds? Is the video of the first, second or third flush after the two minute interval? What I'm trying to do, is set the pressurestat to get a stable 201° reading after the third flush.


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