Freezer only just about gets to 0C when set to -20C

[nmg196]

Hi all,

My Samsung American style fridge freezer has started to struggle to actually get cold. We noticed stuff in the freezer wasn't always completely frozen so tested with a thermometer to find it was only around -3C and sometimes even warmer!

The thermostat's resistance vs temp shows it's working normally. The fan is working normally, but the compressor is on 80% of the time in a regular cycle.

I have use of an IR camera and it seems the radiator coils are barely any different to room temperate but the compressor itself is around 70C and too hot to even touch.

Given it's 12 years old, I don't want to spend too much on it, but these are expensive appliances and if it's something simple like a lack of refridgerant, presumably it wouldn't cost that much to get fixed?

Anyone know if there are any other diagnosics I can do to narrow down the problem so I can get an idea of what's wrong before going down the route of spending £175 on a fixed price repair?

Tha

nks
Nick

 

[nmg196]

PS: I've also noticed that I don't think the compressor always starts when I think it would. Sometimes the relay clicks but nothing actually starts up (12v fan has usually started about a minute earlier).
Maybe I have more than one problem?

 

[JohnD]

Is it a frost-free fridge freezer? Is the fridge part cold?

Surprisingly often this is because the cold-air ducts hidden in the back panel are choked with ice, and the defrost mechanism is not working, so cold air is not blowing into the freezer compartment.

When this happens, the first step is to take all the food out and eat it, and leave the machine, turned off, with both doors open, until it stops dripping, both inside the cabinet and into the evaporation collection dish at the back. It can take a couple of days because there is no movement of air in the ducts once they are solidly blocked, and you probably can't expose them because the parts will be stuck together in a block of ice.

You have to wait until the melt-out is absolutely complete, if you turn it on early you have wasted your time.

Once it has melted out, you can turn it on, restock and shut the doors. If it works for a while, you know what the trouble was. If it chokes again, consider if it happens so infrequently that you can live with it. The first blockage might have occurred when the door was left open; or there may be a failure of the door seal; or the defrost circuit or elements may have failed. This is usually considered beyond economic repair, but some DIY tinkerers have managed to identify and replace the faulty part.

 

[nmg196]

I took the cover off in the freezer area and there was no ice at all. I also found a way to force defost in the service mode and the heating element below the evaporator came on and appeared to work fine.

The external element was also relatively dust free but it simply doesn't get hot. Only the pipe leaving the compressor gets hot but the heat doesn't seem to flow further into the coils. So my instinct is that its a lack of coolant or coolant flow.

 

[JohnD]

So my instinct is that its a lack of coolant or coolant flow.

If that's the real cause, it is beyond repair. My BiL is a HVAC engineer, he does yacht systems and prototypes, won't attempt domestic appliances as he says they were welded tight in the factory, if he has to cut them open, it will never be as good as the factory joints, and they've already failed once.

Commercial and car systems are different because they are made in several components that are designed to be disconnected, rejointed, evacuated and refilled.

 

[nmg196]

I'm sure a domestic applicance repair firm will sort it. You can easily replace the entire compressor if necessary. Nothing is beyond repair if you can get compatible parts cost effectively.
Worst case scenario I can buy a fixed price guaranteed repair for £175 (includes parts and labour), but was hoping it can be repaired for less. It's an American style fridge freezer so would cost £800+ to replace like for like.

 

[plastic_peanut]

In my eyes that’s not an economical repair for a 12 year old unit.

There are plenty to choose from and much cheaper than they used to be. Get a new one bought and get your life back

 

[nmg196]

Yeah that's what we decided to do in the end. It only got worse that day and started smelling of hot oil so we had to switch it off. It's now on the driveway awaiting a swap out