Liebherr CBNes 5067: how to replace defrost heater?

[berauschend]

Dear all,
I am having some issues with my Liebherr CBNes 5067-20B 998849502 fridge-freezer. Every few weeks, the fridge temperature slowly rises until the fridge stops working. Finally I removed the rear panel inside the freezer to find out that the evaporator was completely frozen over. After a few days of defrosting, I measured the connector of the defrost heater and there is no electrical continuity, so I guess that I need to replace this part.

Because I bought the fridge used and the Liebherr Service is really expensive, I would like to fix it myself.

Unfortunately I have no idea on how to get the defrost heater out of the evaporator. The unit looks quite similar to the one in this picture:
https://blog.liebherr.com/appliances/co … r_zoom.jpg

The replacement part:
http://shop.ukwhitegoods.co.uk/6940549- … ost-heater

Here are two pictures of my fridge:

I would very much appreciate it if anyone could help me with that or tell me how to remove the part!

Regards!
Alex

PS: sorry for my English, I’m not a native speaker 🙂

[ELDAR59]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hello Alex, is it the defrost heater that is open circuit, or the thermal fuse?
The fuse is the little black piece at the front with the red and blue wires and it’s likely to be that at fault rather than the heater.

Hope this helps.

[berauschend]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hello Eldar59,
thanks for your reply!
I have stripped the cable between the thermal fuse and the defrost heater, the position is visible on the first picture where the blue tape close to the heat shrink tube on the red cable is. From this point to the connector, in direction to the fuse, there is electrical continuity, but in the opposite direction to the connector there isn’t. Thats what made me think that the defrost heater is faulty.

Indeed there could also be a cable break somewhere in the wires from the heater to the connector.
Regards,
Alex

[ELDAR59]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hi Alex, you really need to be measuring the fuse without the heater in circuit. It’s always more likely to be the fuse than the heater. Of course the heater could be at fault, but without looking at the appliance, I can only talk in terms of probability.

Cheers.

[berauschend]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hi Eldar59,
please correct me if I’m wrong, but I think thats what I have done 🙂
I have measured from the shrink tube to the connector where the blue wire ends and this seemed to work. Measuring from the shrink tube in the other direction, through the heater, to the other cable in the same connector, didn’t work 🙂
Regards
Alex

[ELDAR59]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hi Alex, it does indeed sound like you’ve metered the fuse and it sounds like the heater is at fault then 😆
You’ll need to unclip the front cover of the evaporator to expose the heater. The cover is held on by clips halfway up the back of the evaporator about 10mm in from either edge. If you get your fingers round the back of it you’ll find the clips.
Be careful bending and flexing the evaporator as you could disturb the lokring joints connecting the pipe work.

Cheers.

[berauschend]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hi Eldar59,

that did the trick 🙂 thanks very much!

Now I’m still not exactly sure on how to get this thing out. I have to unclip the heater from the front and back of the evaporator, and cut the wires, then pull it out in direction to the bottom, right?

Unfortunately a few aluminium fins on the evaporator were bent a little bit while removing a cover- is this a problem?

This is how it looks right now:

(I already started bending the clips holding the heater to the bottom of the back cover)

Regards,
Alex

[ELDAR59]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Alex, that looks ok to me. just a matter of unclipping the heater and any connections and then refitting.
don’t worry about the odd bent fin, if you can straighten them, great.

[berauschend]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hello again!

Thank you Eldar59 for your advice, two weeks ago I have managed to replace the defrost heater and it’s thermostat and switched the fridge on again.

Strangely, the fridge now can’t reach -18 degrees at all. After being switched on for >14 days (!) it sticks to -5/-6 degrees and doesn’t get any lower. When I switched it on, it was very warm in my appartment and I thought that might play a role to the increased cool-down process, but two weeks is ridiculous 😉

This wasn’t the case before I replaced the heater. Before, it went down to -18 degrees quite quickly – if I remeber correctly, in approx. 1 day.

Does anyone have an idea why this happens?
I am getting really frustrated with this thing…

Regards,
Alex

[ELDAR59]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hi Alex, is the fan running? Those temperatures are what you would expect if the fan wasn’t running.

Cheers.

[berauschend]

Re: Liebherr CBNes 5067: how to replace defrost heater?

Hi Eldar,
how can I find this out?
Cheers

[ELDAR59]

Re: Liebherr CBNes 5067: how to replace defrost heater?

You should be able to hear it come on when you close the freezer door, or you’ll be able to watch it slow down when you open the door.

Cheers.

[CamdenGuy]

This is a really useful thread, I have a Liebherr fridge freezer with a similar problem. I have disconnected the heater element and stripped back the wire between the element and the thermal fuze and I get a reading of 275 ohms across the element (open circuit across the fuse and heater) which I assume means the thermal fuse is not working. I will confirm this by checking the thermal fuse afer the freezer has got down to -18C again and see if I get open ciruit or 275ohms.

It is getting realy boring having to defrost the freezer everytime the kids forget to close the door poperly!

I assume if it is a problem just with the thermal fuse I can just replace it rather than the whole heater unit?

I will continue this thread with how I get on with solving the problem.

Thanks
Jasper

[CamdenGuy]

I have just measured the resistance of the defrost heater now that the freezer is back to -18C; from the plug it is showing open circuit but when I am measuring just the heater element (bypassing the temperature switch) I get 274 ohms which suggests to me that the temperature control is faulty, not the heater.

The heater element comes withe the temperature switch already attached but I am assuming I could just source a replacement switch which would be much cheaper than the whole heater unit which is about £70. It would also be much easier to fit as swapping out the heater element looks like quite a tricky job!

Any thoughts?

(I did try posting so images but the system seemed to object!!)

[CamdenGuy]

It now appear that my Fridge/Freezer is so old (2006 vintage) that the specified heater is no longer manufactured! So I seem to have the choice of either continuing with running the freezer without auto defrost, buying a new fridge freezer, spending £100 on a thermal fuse from or trying an alternative part. For £5 I can get a 80Degree 240v 15A thermal cutout (the Liebherr cutout is at 93Deg) which I will try. If it does not work the I have wasted £5 if it works I will have stuck two fingers up at Liebherr for trying to rip me off by over changing for a part that should only cost £20.

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