Rancilio Epoca S1 grouphead water temperature

#1: Post by **bjm** » December 29th, 2013, 1:33 pm

I have a 2004 Epoca - the temperature of the water coming out of the group head is 184 degrees and after 15 seconds goes down to 165 degrees. The wand makes steam just fine. What is the next step in troubleshooting this?

#2: Post by **kize** » December 29th, 2013, 6:13 pm

Being an hx machine, your boiler temp (steam + hot water) dictates your hx temp (brew). You never stated what your boiler pressure shows. Your pressure stat controls this. Turn your pressure stat up and then check it.

#3: Post by HB » December 29th, 2013, 7:12 pm

bjm wrote:What is the next step in troubleshooting this?

Troubleshooting what? Do you think the grouphead temperature is too cool? If so, why do you think it's too cool (e.g., sour espresso)? How are you measuring? I ask because 185°F is what I'd expect from a cooking thermometer held in the stream of water. That method is horribly inaccurate; the foam cup technique described in Temperature Differential Between Grouphead and Styrofoam Cup Measurement is the next best thing, but still isn't particularly accurate. You would need a thermocouple + thermometer for some semblance of accuracy.

BTW, you mentioned this espresso machine is nearly 10 years old. Has it been descaled regularly? Scale buildup in the heat exchanger acts as an insulator, resulting in lower than expected brew temperature and faster falloff. For the sake of completeness, below is a video that explains how they work:

December 31st, 2013, 8:31 pm

Thanks for your response. I appreciated the video link and learned a good deal.

I used a Thermoworks temperature probe with a thermocouple to take the measurement of the water as it exited the group (I removed the screen for some of the measurements.) I was under the impression that the temperature should be closer to 194 degrees. Perhaps you are correct and I am not getting an accurate temperature measurement.

The measured temperature also seems to fall off rather quickly. Is this to be expected?

I can't say that the espresso is bad. It actually seems quite good. Maybe I have just become used to what I am getting, however.

In terms of scale. I have always used a Cuno SWC1350-C filter that I change every 6-12 months. Also, I live just south of SF and apparently the water here results in very little scale in espresso machines according to a local espresso repair person. I have never descaled, however. Not sure how descaling is done for this machine and whether I would be able to do it or whether it should be done professionally.