Hello! Last night I tried removing the housing of my Linea Mini but an issue came up where the wheel of the temperature came off ( it easily can be slide in and out so I am not sure where should the wheel be seating in order to get the right number where it belongs

Right now when I put it on the lowest I get this number.





When i put it to the max I get this one




I saw another post but I did not understand it.

I know if you try to go past the max or min it does a clicking sound meaning that it can be re - aligned.

So if anyone don't mind sharing where the 6'o clock seats once you have min and max would help me a lot figuring out where my wheel temperature should be maybe with pictures or whatever you do

I don't wanna pay $600 on a scace for this

Call Chris at La Marzocco Home and he'll get you squared away. I had to replace my potentiometer recently and I just followed Chris's directions to calibrate the wheel. It's easy to do and no Scace is required.

Agreed

dsblv wrote:Call Chris at La Marzocco Home and he'll get you squared away. I had to replace my potentiometer recently and I just followed Chris's directions to calibrate the wheel. It's easy to do and no Scace is required.

i will, i got a mail from Dave and told me that from the lowest point and highest point to do 42 clicks untill you see 203F AT 6'oclock
IF you dont mind sharing, why you had to chance the potentiometer?

is this something similar you had to do, and where can i get chris number?

Elio

That's correct, and it's an accurate procedure. Moving the wheel 42 clicks from the stop puts the potentiometer at the middle of its resistance range. That's equivalent to the 203 degree setting on the wheel. To verify their instructions, I used a digital volt ohm meter to measure the midpoint of the potentiometer's resistance range. The midpoint measured with my DVM was exactly 42 clicks from the stop on the potentiometer. So, either method works to align the wheel.

I had to replace the potentiometer because it failed. It's an analog variable resistance device and oxidation can build up where the internal wiper contacts the resistor. If that happens, the control board thinks you've set the temperature to the max limit and the brew boiler goes into thermal runaway. I was getting flash boiling of water from the brew boiler and the overtemp breaker popped. LM says this problem doesn't occur often, but my machine was affected. To correct the problem, LM recommended rotating the wheel back and forth (with the machine off) on a regular basis to remove oxidation from the potentiometer. But this didn't work after the problem occurred. LM sent me a replacement part at no charge. It turned out to be a relatively easy part to replace. As preventive maintenance, I now rotate the wheel once a week to prevent future problems.

I love using a wheel to set brew temperature since it's intuitive and fast. But, using an analog resistor as the adjustment device isn't the best design. They should have used a digital potentiometer that wouldn't fail this way. It's rumored LM will address this limitation when they release the new control board with bluetooth/app control of machine settings.

dsblv wrote: But this didn't work after the problem occurred. LM sent me a replacement part at no charge. It turned out to be a relatively easy part to replace. As preventive maintenance, I now rotate the wheel once a week to prevent future problems.

Hi, were you provided a procedure to make the replacement? I have the same issue and have the part on the way.
Thanks!

I would contact Chris at La Marzocco if you have questions. Replacing the part is straight forward. Just be sure to unplug the machine before working on it. If I recall correctly, you can replace the potentiometer from the top of the machine and it's not necessary to remove the outer shell. The potentiometer has a cable with a plug on it. The old unit is unplugged from the cable assembly going to the electronics board.

The steps for aligning the wheel are provided in the above posts. The center point on the potentiometer is 42 clicks from the potentiometer stop. This corresponds to the 203 degree setting on the wheel.

NO NO NO!!!!


DO NOT RE-ALIGN IT!!!!


I went through this when I bought mine - and it the real truth is weirder than it sounds.

What you are seeing is the wheel as calibrated by the factory.

The way it is done, is they mechanically align the wheel with the temperature. That's why it is offset. Do not move it or the potentiometer.

I have a SCACE-II because I messed with mine and the only way to restore it to setting is to use a SCACE to measure the brew temperature.

If you take the top off, you'll see some markings done on the frame with a sharpie marker that reference the temperature.

The factory uses a tool like a SCACE to measure the actual brew temperature. Then they rotate the potentiometer to reach a desired number in the brewing range measuring actual water temperature with the tool. Then they put the sticker on the wheel.

And that is indeed, how it is supposed to be!!!!

Do not move it.

The mechanical center point of the wheel is not the calibration point. The calibration point is the actual water temperature.

In other countries, the LMLM is sold with a wheel with a blue and red sticker and no numbers, and they don't calibrate it at all.

I bought the SCACE and restored mine to the factory calibration and it matched what was written on the frame.

My situation is that there's oxidation on certain temperature settings causing issues (flash boiling from the brew boiler). I have a replacement part. Are you saying that it really needs to be done professionally?

Yes, the only way to get the dial number and the actual temperature to match is to use a SCACE tool and position the dial sticker (or loosen the nut on the pot and rotate it) so the number matches the actual water temperature.

SCACE-II tool and Fluke thermometer (note it should be set to T type but it is on K in the photo).

When my dial says 199.4, the average temperature over 20 seconds on the SCACE is 199.4. (which is 93c)

Mechanical positioning of the label is the only means of calibrating the machine.




Here are my calibrated min-and-max rotation positions.

Minium rotation stop:


Maximum rotation stop: