Liebherr Freezer GN2566/ 0976680-07 temperature fluctuations

[flamefix]

Hi,

I'm having temperature issues on my upright Freezer. The freezer will freeze down to any temperature I set on the display but intermittently, and only on the superfrost setting, which led me to suspect the thermostat, however the display indicates a temperature the freezer is currently at. However if it is -18c and I have the door open for less than a minute the temperature can change to -15c which it never used to change by wide a variance if at all. It can also drop to -1c and then take an hour to achieve -5c when prior to being at -1c after the door had been opened it was at -22c.
Some months ago I had herd a grating sound coming from within the freezer compartment as if a fan blade was catching but I haven't located a fan inside the unit and suspect that perhaps the frost free function requires a fan and that is faulty and causing this issue.
The freezer is freezing but I haven't as yet put a probe inside to double check the displayed temperature tallies with the actual temperature, but there is a clear difference from -10c and -22c for example.

I'm a domestic engineer myself in the gas and oil industry so I'd like to fix this problem myself if practical to do so, but in any event I would like to know some idea of the potential issue and cost of repair if I were to embark on having a refrigeration engineer attend from Liebherr for example, particularly if the fault is relatively simple and easy to fix. If it a compressor/ refrigerant side then I will require an engineer but not if the cost is close to the cost of a new freezer!
Many thanks for taking the time to read this.

[spimps]

Sounds like there is frost build up behind the i nner back panel,either take that out where you will find fan and defrost compleytely with hair dryer,or empty freezer and leave switched off for a couple of days and it will self defrost.
You may have a defrost element failure which is also behind that panel which you can also check continuity on.
Could also be a blockage in the drain hole again behind the panel.
UNPLUG before attempting repairs !!

[flamefix]

Thank you spimps, I checked the panel and behind that top panel is a fan and the freezer element and a little brown block I assume to be the sensor wired to the back to the left of the fan.
There was very little ice at all and only on the (I assume ) freezer element but a minute or so with the hairdryer cleared anything that was there.
Everything in the freezer was/is well frozen despite the temperature displaying only -9 prior to starting. I have had the freezer closed now for 30 mins and it was only open for tops 10mins while I did everything but the temperature display is still indicating --, despite everything in the Freezer being solidly frozen. I'll get the Testo out and measure the temperature but does it look more like the thermostat at issue?

[spimps]

Get yourself a quality thermometer and compare the temps

[flamefix]

The Testo is showing -9.8c at the top drawer area and -11.42 at the penultimate bottom drawer. The freezer display is at -7c.

Prior to putting in the sensors the freezer was at -20c it was on fast freeze during the approximate hour of testing the freezer dropped from -20c to -7c the cables to the Testo marginally affected the door seal so I am quite surprised how rapidly it warms up for an A+ rated freezer.

Whilst last night I could hear the compressor kicking in and off I cannot hear it do so, and I expected on fast freeze for the Compressor to kick in within 8 mins. Is the a switch or start capacitor relay etc that fires up the compressor, given that it appears to freeze when it does run could it be something not enabling the compressor?

I have just switched it off, the Testo was still recording the same temp but freezer showed -6c. In 5 mins I will fire it back up and see what happens.
After switching on the display showed nA and was beeping an alarm. I pressed on off and the display returned -9c and the alarm ceased. I pressed fast freeze and nothing has happened. The compressor is hot and there is a faint vibration and a faint buzzing from the box to the left of the compressor. 93989397

[flamefix]

Currently the Freezer is working on fast freeze:
The temperature on the display is -24c and the testo Reads -17.5 top and -19.0 not sure the tolerance of the thermister in the fridge and located on the cooling plate it is likely to read coolant temperature rather than ambient temperature, which explains the discrepancy.

It would seem to indicate the compressor works but may not always be switching on?

[madvic]

Hi I have the exact same problem as you describe did you find what the problem was, many thanks.