MIELE KF7654 SNE Temperature Sensors

[cl1972]

I have a MIELE KF7654 SNE Fridge Freezer Nr 57774940. It was giving an F4 error code so I got a new sensor, part #9590206. Unfortunately when i installed it I mistook F4 to be the air sensor so I replaced that and then discovered that F4 was the evaporator sensor. So I then removed the evaporator sensor and attached the sensor that used to be the air sensor.
This removed the error codes so I set the temp to -18 and turned on the freezer. The freezer display dropped to -18 but it was really approx -4 when I tested using a standalone temp reader. If I set the freezer to -28 and turned on the super freeze the freezer display then read -32 but the real temperature is -18 .
I then measured the resistance of the sensors by removing the circuit board connections and testing them.
The two sensors gave very different readings. For instance with the new 4.7K ohm sensor (placed in the air sensor position) has a much higher resistance than the original working sensor (placed in the evaporator position)

at 0C (placing sensors in water bath)
new 4.7K ohm sensor 16.4K ohm
original working sensor 12.4K

at -15C (freezer says -30C)
new 4.7K ohm sensor 44.2K ohm
original sensor 15.1K

at 16C room temp
new 4.7K ohm sensor 7.1K ohm
original sensor 2.9K

So the new sensor always has a higher resistance than the original working sensor
For the record the original bad sensor reads 200ohm at room temp.

When the freezer was at -15C and the freezer display was reading -27C I placed the new sensor in hot water at 50C, the freezer display stayed at -27C! Very confusing.

Is the 4.7K sensor the correct one for my freezer?
If the two sensors have very different resistances will this confuse the freezer?
Why would the freezer display not rise from -27C when I placed the air sensor in hot water?
My assumption is that all the sensors in the freezer are the same, maybe that’s a bad assumption.

Any help would be very much appreciated,
Conal

[electrofix]

Re: MIELE KF7654 SNE Temperature Sensors

you have really answered your own question. The two sensors obviously have different characteristics, and since the electronics rely on the resistance of these sensors to control the appliance, it is safe to assume if they are different values you will get different results

Dave

[cl1972]

Re: MIELE KF7654 SNE Temperature Sensors

Thanks Dave.
So does anyone know the correct type of resistor to use?
The new sensor is 4.7ohm and afaik it is the correct replacement (#9590206)
Either the original sensor that is still installed is starting to failing like the one I replaced and this would explain the different reading or the new 4.7ohm sensor is not the correct one to use.

[Tony R]

Re: MIELE KF7654 SNE Temperature Sensors

Resistance changes as it senses the drop or rise in temperature.
Just checked the parts diagram, sorry you have fitted the wrong sensor, the 9590206 is not the sensor repair kit for the evaporator on your model, and the air has no repair kit option and has to be the exact part.
Regards,
Tony.

[cl1972]

Re: MIELE KF7654 SNE Temperature Sensors

Thanks Tony,
Do you know the correct part number for the evaporator sensor?

[Tony R]

Re: MIELE KF7654 SNE Temperature Sensors

I can confirm the correct part numbers if you can give me the index number on your unit, it is on the rating plate after the model number, as there are several versions, but all are Liebherr made and the Liebherr parts will be cheaper on this site.

[cl1972]

Re: MIELE KF7654 SNE Temperature Sensors

Hi Tony,
It’s 57774940
Thanks,
Conal

[Tony R]

Re: MIELE KF7654 SNE Temperature Sensors

Sorry Conal, that is not the index number, it is directly after the model number and will be something like 164-22
Regards,
Tony.

[cl1972]

Re: MIELE KF7654 SNE Temperature Sensors

Sorry Tony, I think 164 25 is the one you need?? See the attached image

[Tony R]

Re: MIELE KF7654 SNE Temperature Sensors

Freezer Evaporator sensor 6942799 Freezer Air sensor 6942118
Regards,
Tony.

[cl1972]

Re: MIELE KF7654 SNE Temperature Sensors

Thanks Tony,
The sensor resembles the old bad one more than the replacement I got so I’ll go ahead and order one off this site. The cable looks a bit short and the connector does not look like a match I’ve no problem snipping off the connector and attaching to the end of the existing cable.
Many thanks,
Conal

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