ECM Mechanika IV grouphead temperature too high

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
ppaolo2
Posts: 113
Joined: 7 years ago

#1: Post by ppaolo2 »

Hello,

I have this issue with my 2013 ECM Mechanika IV. The grouphead temp measured with Eric thermometer is idling at 96°c. I had to lower the temp by lowering the max boiler pressure to 0.8bar down from 1.4bar or I would get almost 100°c. Could this be caused by scale on temp sensors or it's something else all along? Before I replaced my stuck overpressure valve, I was normally getting 93°c max at normal 1.4bar. I was thinking to just pull out the temp sensors and see if there was some scale, is there some gasket or anything that must be replaced or I can just take them out and put them back easily?

JRising
Team HB
Posts: 3670
Joined: 5 years ago

#2: Post by JRising »

When it has been idling for less than 4 minutes, does the grouphead get up to 96C, or does it take a longer idle to get it up there?

How long a cooling flush do you tend to have to do to get liquid from the shower filter after it has been idling for more than 8 minutes?

You talk about "temp sensors" like it's a PID machine, but discuss adjusting the pressure rather than the temperature. Can you explain? I'm not sure I unbderstand what's wrong with the machine. An idle HX needs to shed its heat from the grouphead, the grouphead will get hotter than your target brew temp. if allowed to idle, but should be easily and quickly returned to brew temp with the cooling flush.

User avatar
HB
Admin
Posts: 21984
Joined: 19 years ago

#3: Post by HB »

ppaolo2 wrote:The grouphead temp measured with Eric thermometer is idling at 96°c.
That sounds reasonable for a heat exchanger. Keep in mind the E61 thermometer temperature reading only closes in on the actual brew temperature during the final seconds of the extraction. Prior to that, the reading really isn't helpful, at least from an absolute point of view.

I suggest watching this video:
And read HX Love and HX Ideal brew temperature management.
Dan Kehn

User avatar
Jeff
Team HB
Posts: 6808
Joined: 19 years ago

#4: Post by Jeff »

Depending on the machine, it is not unusual for the idle temperature of an E61 HX, as measured with an EricS group-head thermometer, to get up above 100 °C or into the "two-teens" °F. Because the brew circuit is closed, the pressure can rise in there enough that there isn't boiling, at least until you start to flush.

ppaolo2 (original poster)
Posts: 113
Joined: 7 years ago

#5: Post by ppaolo2 (original poster) »

Thanks for your reply. My bad, I mistook the safety temp probe for a temp sensor, so it won't make a difference cleaning them.
The issues is that even if I do a longer flush like 8 sec, the temp drops a bit to 94/95 but then when raising the lever to brew the espresso, it goes up again to 96 and slowly gets down to 93/94 at the end of the shot.

Maybe I should just do longer flushes?
I also eed do a light descale anyway since it's more than 3 years and I'll see if it improves anything (but I don't think so since I just light scale)

User avatar
Jeff
Team HB
Posts: 6808
Joined: 19 years ago

#6: Post by Jeff »

As long as the pattern of how you flush and when you pull your shot relative the the temperature after the flush is consistent, you'll have reasonably consistent extraction temperatures. If you want it hotter, for example, you can wait for a higher temperature on the rebound if you're using "flush and wait" or a higher temperature when you stop the flush if you're using "flush and go".

With virtually all machines, the shape of the temperature profile during the shot is whatever it is. There is nothing I know of that supports the idea that constant temperature during the shot is "best".