Neff Fridge/Freezer Switching itself off.

[Builder Geoff]

I've got an American Style Neff fridge/freezer about 18 years old, never had a problem except for a blocked drain.

But now I've got a proper issue. Having learnt how to replace PCBs, motors and drum spiders in my washing machine, I'm determined to work out how to fix this one.

If I turn it off at the socket for about 10 seconds and then turn it back on, it appears to start fine. Display normal, internal light OK, etc. Once the compressor has been running for about 10-30 seconds, it seems to switch itself off completely, display off, internal light off, silent. The only way to start it up again is by cutting the power at the socket for about 10 seconds. It seems like an electronic issue rather than electric.

Since the compressor is working, I'm guessing that the compressor and the thermostat seem to be OK. My guess is the PCB has gone rogue. I can't find anything online of similar problems.

Any ideas?

Thanks.

 

[accelerator]

Have you tried asking Neff?

 

[Builder Geoff]

I contacted Neff with details of the problem. They replied and said they were not technically trained and I would have to arrange a Neff engineer to visit to diagnose. I can get a new PCB for less than the cost of an engineer visit which I'm tempted to try but hoped someone on here might have some experience of fridge/freezer issues and whether the PCB is likely to be the cause.

I don't like things to go to waste and this is a lot of white goods to end up in landfill for what is probably a small replacement part.

 

[accelerator]

Could be a Faulty Compressor Start Relay or Overload Protector, and the PCB is shutting it down as a safety feature.

 

[Builder Geoff]

Thanks for the suggestion. I had no idea that there would be a relay in there, and having checked some YT videos I can see how to test it. I'll have to pull out the fridge and find it.

 

[Harry Bloomfield]

I don't like things to go to waste and this is a lot of white goods to end up in landfill for what is probably a small replacement part.

My first check, would be to test the mains supply is OK, all the way to where it enters the inside unit. It would be silly to delve deeper, until you have made sure of that first....

Connect a lamp holder, and bulb, across the mains terminals, inside the unit, and ensure that stays on, as a first step. It might be something as simple as the fuse, in the plug, loosing contact, as it warms up.

 

[foxhole]

Could be loss of gas, it will run briefly till safety shut off. At 18 it’s time for retirement .

 

[ericmark]

I would not attempt to repair my fridge/freezer or freezer, I know the basics, it turns the single-phase into DC then DC into three-phase which drives the motor, but how the inverter is adjusted not a clue.

Older units had single phase motors, but in my attempt to repair a very basic unit, I found getting the correct parts was not easy.

Back in 1982 I used to repair freezers, but even then I could not gas them up. Every so often, I put my freezers on an energy meter and see if using more energy, it tells me if they are still cycling on/off, or working flat out, which tells me how likely they are to fail, there was a 10-year warranty so they are designed to run for many years, but at 18 years I would say ready to retire.

 

[Johntheo5]

I have a 17 year old Hotpoint Fridgefreezer still working fine wich has displayed the above symptoms for years, if not forever. On a normal restart after cycling off for say 45mins or so it starts up at around 110watts and over the course of 30 minutes or so will decay to 80/85watts and cut out at around 75watts. But if you switch off the power even if it has been running for 10 mins or so and restart it immediately, the power goes up to 650/750watts and the compressor then trips on what I imagine is a thermal overload, it will then reset/restart a few minutes later at its normal 110watts.

 

[Builder Geoff]

Thanks for all the replies - certainly some food for thought.

Thanks to the advice of some YT videos from Amre Supply, I removed the starter relay and the overload protector and did a continuity check. I was expecting resistance of 0-1 ohm through the protector - I got 0.4. I expected between 3-9 ohms through the relay, I got 38. On that basis, I suspected that the relay was faulty. As it was cheap enough, I replaced both and tested them before fitting - 1.3 ohms and 4.7 ohms respectively so better looking numbers.

However, having fitted them, I've got exactly the same symptoms. I realise I don't need to turn it off for a specific period of time, but once turned on again, the compressor runs for anything from about 10 seconds to 1 minute before everything shuts down. Perhaps the compressor is at fault and the overload protector is doing it's job, in which case I agree that replacement of the whole unit is the way to go. But I have to question why the whole thing shuts down, including the LCD display - would it not be better for the PCB to detect, shut down the compressor and display an error code instead? This is the type of thing that suggests to me that it is electronic rather than electrical, mechanical, or even chemical. I could replace the PCB for about £100 but obviously that is money down the drain if the compressor (gas or otherwise) is the problem.

I had similar issues with my washing machine. Under a year after replacing the PCB, a problem occurred where the cycle would just stop progressing and would sit doing nothing, displaying the same remaining time indefinitely. My PCB supplier was very accommodating, suggesting the motor was at fault. I was incredulous - of course not, if that was the case, either the PCB would not register the failure of the motor to operate and the time would continue to count down to zero and the drum would just not turn, or the PCB would notice the problem and display an error code. After trying a new PCB, it turns out they were right - I replaced the motor and it's running fine again now.

Have I got a similar situation with a dumb fridge/freezer? The info is available to the PCB, but instead of trying to report it, it just shuts down the whole machine.

 

[accelerator]

Go to https://copilot.microsoft.com/

Then paste in "Why is my Neff fridge/freezer not working? If I turn it off at the socket for about 10 seconds and then turn it back on, it appears to start fine. Display normal, internal light OK, etc. Once the compressor has been running for about 10-30 seconds, it seems to switch itself off completely, display off, internal light off, silent. The only way to start it up again is by cutting the power at the socket for about 10 seconds. It seems like an electronic issue rather than electric."

You will get some more things to look into. Let us know how you get on.

 

[Builder Geoff]

That's brilliant - I'm a bit of a dinosaur and hadn't considered using AI. That gives me a few more things to poke around with before asking my friendly refrigerator engineer to have a look or to chuck it in the bin.