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DeLonghi ESAM 4200 water tank empty warning when tank full

45K views 17 replies 17 participants last post by  pnb 
#1 Ā·
From looking online I know that you can overcome this problem by adding a more powerful light rare earth magnet to the top of the float in the water tank, or by shorting out the reed switch connectors on the control board inside the machine (although this fix means the machine thinks there's always water so not ideal) however because I'm fixing this problem for a friend I'd like to solve the problem "properly".

First I bought a new DeLonghi ESAM4200.S reed switch to replace the one internally. Fitted it but the problem remained. So I then bought a whole new water tank because I couldn't find a supplier selling just the float. The new tank with new float made no difference even using the new sensor.

Since the design seems simple I can't see what the underlying problem is. Any ideas? Thank you...
 
#2 Ā·
Managed to fix this.

Unplugged machine from electrical supply. Removed water tank. Removed sides and back of machine. Remove the six screws on the rear. The sides slide backward slightly before they can be pulled off. Filled water tank and replaced in machine with sides and back still removed.

On the inside left of machine, moved the white water level sensor reed switch closer to the magnetic float In the water track by removing the switch from its screw fixing and using an ultra thin sticky pad to stick the switch adjacent to the position of the float in the water tank.

By removing the air gap on the inside of the machine it seems that the magnet is sufficiently close to get the reed switch to close when the tank isn't empty.

Hood Vehicle door Motor vehicle Font Gas


Why I needed to do this with a new reed switch and a new magnetic float I can't explain. Very odd.

Machine now working.

ED
 

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#4 Ā· (Edited by Moderator)
I came across a very lightly used Delonghi Magnifica ESAM 4400 and it had the same issue of getting "Fill Tank" message when there was plenty of water in the tank. I had been pushing on the water tank when this frequently happened to be able to hobble along, but thankfully after much searching I came across Ed's post with solution contained in this thread. I just want to say THANK YOU for the fix! I moved the reed sensor as pictured and the issue is resolved. I used some Scotch Tape to first position and tack the sensor in it's new position and then used 3M Electrical Tape to secure the sensor permanently. See pic of sensor repositioned to the left of the screw that was used to originally secure the sensor as manufactured by Delonghi.

(Oh, I rethreaded the wire of the sensor to give it a bit more slack to ease the repositioning and to not put too much pressure on the wire as it goes into the sensor. See the second pic and look to the lower left and you'll see how I moved the skinny wires attached to the sensor and rethreaded through the water tubes.)

. Gas Cable Computer hardware Electrical wiring Machine


Automotive tire Hood Alloy wheel Automotive lighting Bumper
 

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#5 Ā·
Had the same problem where the machine said there wasnƂ't water in the tank. I removed the black magnet from the water tank and taped it to the white sensor. Will have to make sure water is always full. Not sure what will happen when I have to rescale/clean the tubes again. Thanks for the help!
 
#6 Ā·
Rrc23 said:
Had the same problem where the machine said there wasnƂ't water in the tank. I removed the black magnet from the water tank and taped it to the white sensor. Will have to make sure water is always full. Not sure what will happen when I have to rescale/clean the tubes again. Thanks for the help!
Thanks for your post. I also removed the black magnet from water tank and wedged it against the sensor. My machine is still going strong after 14years daily use.
 
#11 Ā·
Many thanks for all the help with this issue and for highlighting what the problem was. Rather than moving the sensor I managed to fix it by placing a very small 3M mini magnet on the side of the water tank just at the top of the float housing. It seems to have done the trick without the need to rewire the sensor.
 
#12 Ā·
I thought our machine had the same problem. It kept saying 'Tank empty'. So, I started searching by taking out the float and approaching the sensor with it. The machine beeped, they found each other. So, what could be the problem? It took me one hour to realize that seeing each other meant the tank is full. Not seeing each other meant that the float was too low in the reservoir to be seen by the sensor. So, where was this sensor with a full reservoir? At the top of this little box in the reservoir, hold by a demountable cap. This cap can be mounted in two ways and this was the problem. One way: float is seen; other way: float is not seen (tank empty warning). Placed the cap in the differtent position and problem solved. (My partner hadn't mentioned that the cap had come off).
 
#13 Ā· (Edited by Moderator)
I have the same problem with a 4200s, water light staying on. tried the magnet trick and that doesnt work, oir the cap repositioning.

I saw one of the posts on here saying he has had his Delonghi for 14 years. I would suggest keeping that bean to cup machine as long as possible.The new Bean to cup machines only last just over 2 years. My one is 2.5 years and it leaks badly, not at the water tank seal but internally. I have replaced the faulty steam wand.

Now this a water level fault which does not allow the machine to switch on.

The 4200S is like all goods nowadays, cheap and only last a couple of years where they used to last a long time, now they are designed to fail just out of warranty.

I.ll probably have to strip it down again....jeez it is such a badly designed machine, you cant fill the water tank on the fly.
 
#14 Ā·
Had same issue and solved it with a mechanical trick too, without unscrewing anything (although those posts helped me understand the issue). I removed the little plastic cap that holds the magnet in the water tank and cut off 3 mm of the pin so that the magnet can move higher up when the tank is full. Problem solved, no empty tank warning anymore, except when the water level is low - which is the purpose.
 
#15 Ā·
Different model but same issue, make sure the black 'rectangle' piece inside the tank (in mine it's in the middle, at the bottom), can move up and down freely on its 'rails'.
I nudged it first, then noticed a bubble of air above it, so I slightly tilted the filled tank a bit. The air bubble came out and the black 'rectangle' floated back up to the top, with the machine recognising a full tank again.
 
#17 Ā·
I replaced the sensor inside from an ebay second hand. Problem still there. I sticked a magnet in the water tank. Solved for few minutes. After one coffee, the red light of water level error show up again. I am running crazy!
When I take the water tank and touch again with a magnet against the sensor, light goes off. Put back the full water tank and makes one coffee. Than again red light on. I don't think replacing the water tank will solve the problem.
Delonghi Magnifica 4.110s.
 
#18 Ā·
You replaced the hall sensor in the machine or the black float with the magnet in it, in the water tank?
Do not put a strong magnet near the hall sensor as you may alter it's sensitivity permanently.

Normally this is the black float leaking internally (poor design) leading to a rusting magnet that loses it's field effect gradually. Hard to get it out (see my post history) but is possible to repair if you have a small neodymium magnet to grind down and fit and deal with orientation, sealing and floating issues thereafter.
 
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