Hanseatic Side by side refrigerator Cools down and then heats up

[nile88]

Hersteller: Hanseatic

Typenbezeichnung: Side by side refrigerator

E-Nummer: Model: HSBS 17690A2S ; Artikelnummer: 323953

kurze Fehlerbeschreibung (2-3 Worte): Cools down and then heats up

Meine Messgeräte::
Analog/Digital Voltmeter

Schaltbild vorhanden?:
Nein



Hi everyone,

First of all, greetings from Serbia.

I have strange situation with my SBS refrigerator. Thing is that it cools fine. Temperature going on setpoint in both section. Also I did additional measuring by digital meter + probe. It runs down on temperature which is chosen by operational display.

Thing is that heater (defrost) is actuated too often (or too long), and temperature goes up too much, it goes into +.

Evaporator is in freezer compartment. Refrigerator compartment is cooled by importing air from freezer chamber.

At evaporator, I found attached thermo-diode (77 Celsius) as a protection, heater (which is checked and it is ok) and there is also one sensor connected on top. I assume that is a defrost sensor. When measuring, at room temperature it shows around 2kohm. When heated by hand, resistance goes down. There is also one sensor on the left wall of freezer. It is probably ambient temperature sensor. Haven't, measure since wires goes into wall, and then somewhere on the mother board.

My idea was to find new defrost sensor, but its not available at our market.

Since I stuck, is there any suggestion what should I do now? What can cause this situation?

 

[nile88]

Update:

Refrigerator works fine. Temperature is stable at 5 Celsius (as setted up at display).

Freezer temperature vary from minus to plus and repeated cyclically.

Does someone have info about reference value of defrost sensor, and ref value of ambient sensor??

As my knowledge reach, most of the defrost sensors are NTC of roughly 5kohm at room temp... Mine (measured) is 2kohm.... If I put 5kohm, probably nothing won't go wrong. Just, if the value of replacement NTC is not correct, temperature in the freezer will be higher/lower than preset, but the first point is to calm defrost cycles down. I will go that way