Troublesome Lelit Mara PL62 (beeps)

Equipment doesn't work? Troubleshooting? If you're handy, members can help.
hpk11
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#1: Post by hpk11 »

We've owned a Lelit Mara PL62 since Nov. 2018, have been pleased with the espresso pulled. Unfortunately, about 3 weeks ago, it started beeping, (water tank empty signal), though the tank is full. Shaking out the water tank, that has a magnetic float part of the water sensor system, helped. However, the problem intermittently still happens when the machine is hot, after we've pulled a few shots. Never when cold. I replaced the water tank with a brand new one, also pulled one of the microswitch sensor wires. (read that workaround right here on home-barista). The problem still happens. Always when hot.

Anyway, I've been email-ing 1st-line, who have an email only policy, and when I request parts from a parts diagram, tell me it's the wrong diagram. What am I supposed to do? I guess they want the 50 lb.machine shipped back to them, which I'm unwilling to do until I've exhausted my own resources. Anyway, the parts I've requested are these :- the read sensor (9600009) and the 3700035. Looking for confirmation and help, this site has been really good, all sorts of tips over the years!

Thanks!
-h

kitt

#2: Post by kitt »

Hi, usually caused by broken plastic tees or hose connections dripping down onto the microswitch. Do you have a picture as i'm not sure how they're configured in the USA? or the teflon hose that goes down to the HX feed has a split and drips onto the microswitch. Or the microswitch has just gone bad, try replacing that?
Try running it hot with the top cover off to see if any leaks

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BaristaBoy E61

#3: Post by BaristaBoy E61 »

I would glue a magnet to a chopstick and when this symptom occurs I'd remove the reservoir tank and see if the machine operates normally with the chopstick & magnet held directly on the magnetic sensor. If this corrects the fault then the sensor is probably OK and the heat might be causing an increase in distance between the magnet and the sensor weakening the magnetic field effect.

Is the sensor properly fastened to the chassis? Have you tried swapping the floats in the reservoir tanks around and then trying each reservoir tank again?
hpk11 wrote:also pulled one of the microswitch sensor wires.
What does that mean? If it's a 'Reed' switch then shorting it's 2-wires would bypass the sensor and the fault condition would go away. However, you would have no low water protection of your boiler heating elements and could burn them out if run with low or no water!
"You didn't buy an Espresso Machine - You bought a Chemistry Set!"

hpk11 (original poster)
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#4: Post by hpk11 (original poster) »

TQ, @kitt, @BaristaBoy E61 for the tips.
Will have to work on the Mara this weekend, there're almost 20 screws to get to the inside!
- will try the "chopstick" test. :)
- recheck hose and other connections, I did the last time I pulled apart the mara, but the inside is tight, and may have jiggled some the wrong way.
- take an "insides" picture and post

@BaristaBoy E61, regarding your q.
The water tank is 2 weeks new, as I did find that shaking the tank (and float) would resolve the problem for a few days. Regarding pulling a wire to stop the beeping and the safety issue of an empty tank - we just make sure that the tank is full. Hubby and I pull 6-8 shots plus a batch of milk, so it's not a problem - we're careful to check.

Thanks,
-h

JRising

#5: Post by JRising »

I'm not sure if I'm missing something, there seems to be more than one thing being answered here when the question was about the parts.

If we can clear up how the machine works it might help explain the bad switch. The low-reservoir water alarm makes a beep beep sound when the reservoir is out and/or there is a magnet near the reed switch. It will not protect the machine, it will beep and if it gets your attention, you can fill the reservoir.

The limit switch and reed switch are wired in parallel. Limit switch is NC, held open when the reservoir is seated. The reed switch is NO, and closes when the magnet floats down too low and closes it. When either switch closes, the alarm beeps.

It's possible that the (Sealed, fairly water resistant) reed switch has been damaged and when it gets warm passes some current and triggers the alarm despite the magnet being nowhere near it, but it's much more likely that the limit switch with virtually no protection from water at all has gotten damp and passes a bit of current at times even when held open. I would inspect and replace the (probably cheaper) limit switch before the reed switch.
Posibly Lelit 9600010 but I'm not going to swear by parts for a Lelit machine I can't physically see.

hpk11 (original poster)
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#6: Post by hpk11 (original poster) »

Hello @JRising,
Correct, I'm asking about parts that I did research, but also taking into consideration additional tips.
Here is the pdf provided by 1st-line,
https://www.1st-line.com/wp-content/upl ... -REV02.pdf

Cut/paste screenshots, pg.3 and 4, Center top of page.




THank you!
-h

JRising

#7: Post by JRising » replying to hpk11 »

AHH, I see... So the actual reed-switch holder is different and mounted from below if your serial number is newer/higher than 77950. But the reed switch and limit switch are still the same part numbers.
If my memory is correct, the parallel switches are jumped at the limit switch (reservoir switch) If you take the paired connectors off of the switch, but still leave the wires connected to each other and insulated from the body of the machine, the magnetic float switch will continue to work just fine. If you run it like this you're safe to not run out of water so long as the reservoir stays in the machine, and if it goes all week without beeping, you've further proven that the reservoir limit switch is the baddie.

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hpk11 (original poster)
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#8: Post by hpk11 (original poster) »

JRising wrote:If you take the paired connectors off of the switch, but still leave the wires connected to each other and insulated from the body of the machine, the magnetic float switch will continue to work just fine.
ok, I pulled one of the connectors, so I should pull both? Let me give that a try.

Thanks for the workaround.
-h