The solenoid coil on my Minima stopped working last year (after only a few months of buying it) but thanks to help from ACS and people on this forum I managed to fit the replacement sent to me. Now the Brew Temperature Sensor has gone south and a replacement has been sent. Unfortunately with no instructions about how to fit it. After asking I was pointed to this video: https://drive.google.com/file/d/16pVJXJ0yKJ0q1HJgTDtGpb-fD_DVM8vN/view but there are no instructions about what the tubular object into which the sensor is being fitted. I imagine it to be the brew boiler, but my question is: how to I remove that boiler - might anyone be able to help this idiot get espresso back into his life? Thanks in advance Durn it, I've just noticed there's a General ACS Minima Thread I should have posted in. Sorry, can't see how to move this post.

It's a super easy replacement, they just have the boiler out to make it easy for you to see. **You absolutely don't need to remove the boiler!** > @"Java_avaJ"#p40871 but there are no instructions about what the tubular object into which the sensor is being fitted. It depends which boiler the sensor has failed on, steam or brew, but the procedure is the same, just replace the correct one. The existing ones on your machine are probably vrass coloured ones with red or black wires coming from them. ACS now use a much more expensive stainless steel replacement, as their tests showed that the manufacturers ["potting"](https://etcorp.ca/what-is-potting-and-why-is-it-used/#:~:text=You%20may%20have%20heard%20the,apply%20this%20is%20called%20potting.) in brass sensors commonly used in the industry expanded and contracted, eventually breaking the wire, it could take years to do this. You simply: * disconnect the wire, there is a midpoint connector * Unscrew the old sensor and screw in the new one with 8-12 turns of PTFE tape (or whatevers required so it doesn't leak * Then reconnect the sensor wire If you are not sure what's what, remove the lid of your machine and past a photo, then it can be explained for you.

Oh that's brilliant, I'll give it a go tomorrow and upload a photo if things aren't clear. My assumption was that it was the brew boiler because the the entire E61 (?) assembly above the grouphead was cold and the pid showed an A2 error code. Which I think is brew boiler.

I've found the part that needs replacing, and you're right @"DavecUK"#p40876 there are two red wires coming from a brass fitting. Unfortunately, said two wires disappear into the bowels of the machine and behind the stainless box that holds the water reservoir so it'll need more dismantling that just taking the top off… OK, I'll get down to it 🙃

Jeez, @"DavecUK" sorry to bother you, but any thoughts on what I have to dismantle to get to the end of the red connector? [URL=https://i.imgur.com/wvN3hRT.jpg][IMG]https://i.imgur.com/wvN3hRT.jpg[/IMG][/URL] Removing the cage around the water seems tricky to say the least, screws hidden.

If you look carefully you will see a cable tied bundle beside the boiler, very carefully snip the cable tie **if you need to** and then there is a small connector that can be pulled apart. The wire actually terminates in the bottom of the machine on the Gicar box, but that can be awkward to get to. I think it's easier to use the little midway connector. The sensor should come out very easily as it has been installed using PTFE. I don't know if that's from factory or whether it had a previous replacement. be careful not to twist the wires about when installing.

ACS Minima Temperature Sensor replacement

Java_avaJ

Yes, a pair of long tweezers extricated the double red cable from the others and it slid about inside the cable tie holding the bundle enough to pull the little plug of the cable connector from the socket. So I got it out.

Then I had what thought was a bright idea of threading the cable from the new sensor into place and connecting it before I had to take up the slack and screw the bolted sensor end into the boiler. Of course that meant that as I turned the threaded bolt into place the wire twisted. Doh. Once i undid it and re-did it it went together fine, albeit not cable tied into place.

Now, no error code and correct temperatures. Thanks @DavecUK for the help. 👍

DavecUK

Java_avaJ Doh. Once i undid it and re-did it it went together fine, albeit not cable tied into place.

I added my P.S. Too late…was the replacement a stainless steel one?

Java_avaJ

Yes SS

DavecUK

Java_avaJ Yes SS

Excellent, you really shouldn’t get any problems with the SS ones for a long time. ACS have changed over to them.

Java_avaJ

I just made my first espresso. And it’s strange, in fact I had the same symptoms before the temperature sensor showed the error code and the E61 was cold. The symptoms are the coffee runs out in a vigorous stream, just as though either the grind was too course or it wasn’t tamped enought. But the grind is exactly the same (via my Niche) and the pressure should be the same since I use a leveller I’ve not adjusted and tamper that gives the same prressure every time. The water temp is the same and the water pressure shows the same in the gauge on the E61.

Any thoughts?

DavecUK

Java_avaJ make a video, showing the temperatures and the A2 error?

This is because you are actually telling us very little and I want to be able to help.

Java_avaJ

Sorry Dave, I’ll make a video. By the way there is no A2 error now I’ve fitted the new sensor. I’m just mentioning that the very very fast flow rate was a precursor to the A2 error and the sensor fail. But I’ll make a video it’s just that the answer I’d give is grind finer, tamp more firmly, whereas I’m doing exactly what worked for the 10 months prior so I was hoping you might say: “ah, that’s the dohinky about to fail and you need to turn it clockwise two turns” 😜

DavecUK

Java_avaJ I’ll make a video. By the way there is no A2 error now I’ve fitted the new sensor.

Also give details about:

type and roast date of coffee
single or double basket
weight of ground coffee used
age and make of grinder
anything else you think is relevant?

Java_avaJ

Just made a video and wouldn’t you know the problem I describe, that the coffee brews very quickly giving 37gm in about 15 seconds, didn’t happen. It’s odd, my process is always the same. I’ll make a few more videos, hopefully I can catch it on film. I mentioned it because it happened a lot before the temperature sensor failed and I’d wondered if the two were related. In the meantime here are the answers to your questions:

it’s French Roast bean that is normally roasted the same week I buy the beans and I use the beans (1kg) in about 2 weeks.
Single basket, naked, 18g VST
18.5g coffee in, 37g out, 1:2 in other words.
Coffee grinder is a Niche and it’s about 10 months old
I use a WDT to level slightly and break any lumps, then I use a coffee distribution tool, and finally I tamp with a calibrated tamper. In other words I would think the puck is fairly consistent and there shouldn’t be any reason why my habitual 37g out in around 30 seconds should drop to 15 seconds.

I really do appreciate your help @DavecUK - you really go over and above.

DavecUK

Java_avaJ I don’t think the problem is related, perhaps the puck fractured during the shot?

Eyedee

I’ve just had the error code A2, where would I have to go to get a replacement thermostat, would it be a request to ACS ?

Many thanks

Ian

DavecUK

Eyedee It wouldbe, contact Maria. You will be able to get the far more reliable stainless thermostat they use now.

Eyedee

Thanks Dave, do you happen to have an email address for her ?

DavecUK

Eyedee sales@mevsrl.net or service@acs.com