Samsung RS21NSCV

[Peter Ascough]

:confused: :confused: I have a Samsung RS21NSCV American style fridge freezer which is about 2 1/2 years old. It developed a fault whilst still just in warranty (Nov 2005), the fault being that the fridge section kept freezing up to the extent where the fan blades caught on the build up of ice and made a noise. An engineer replaced something behind the plastic panel covering the cooling tubes. A couple of months ago it started doing the same thing again, and I am having to defrost it almost weekly:mad: :mad: by removing the shelves and then the cover in the back compartment of the fridge. Does it use a thermistor for temperature sensing or could it be that the de-frost heater is not working? Any suggestions as to what the problem might be would be greatly appreciated.

[Brian_UK]

Sounds like a familar problem according to the UK Whitegoods website.

Have a look here:-
http://www.ukwhitegoods.co.uk/modules.php?name=Forums&file=viewtopic&t=7207&highlight=samsung

I did a search on 'Samsung' ;)

[Peter Ascough]

Thanks for the reply. I went to the website you gave a link for and although it mentions a problem with freezing up, it doesn't mention a cure - other than manually removing the ice as I am doing. I was rather hoping someone could point me in the direction of a faulty component (I work in electronics so component and circuit checking is not a problem for me).

Thanks again,
Peter.

[davej]

hi peter we have had problems with samsung and getting technical info is a nightmare, the whitegoods webb site is your best bet i think, but be prepard for a lot of trial and error

[Peter Ascough]

Hi Dave,
Thanks for the reply. I have e-mailed Samsung and suggested that there may be a problem with this model when you look around web sites and see how many people have similar problems. I did suggest, that in view of all the problems people are reporting and the fact that the problems occur on quite new units, then the product may not be "suitable for purpose". I will await their response before I decide on the next step (small claims court?). I wonder what other people with a similar problem feel about this approach.
Regards, Peter.

[superfly]

Common problem with the rs21's. Check evap heater 470ohms drain about 2kohms,check thermal fuse.If all checks out ok and evap is completely frost-evap sensor faulty.
no frost on evap-check evap cover.this can retain water causing it to ice up around fan.Defrost cover and under the fan motor there is a channel.make the hole larger to stop it retaining water.It needs to defrosted thorghly to remove any ice in channels of cover.

[Peter Ascough]

Hi there,
Many thanks for your informative reply to my query. A shame I didn't read this earlier as I have just had the cover off to defrost the fridge yet again. When I last defrosted it I did check the thermal fuse and the drain - both were o.k. according to your values. The evaporator coils were totally iced up, and ice forming on the polystyrene housing around the fan blades!! Not being a refrigeration person, where is the evaporator sensor, and the evaporator heater situated, what do they look like and how can I check the sensor? I hope I am not being a pain asking all these questions. Once again, thanks for your response.
Regards, Peter.

[Makanic]

Common problem with the rs21's. Check evap heater 470ohms drain about 2kohms,check thermal fuse.If all checks out ok and evap is completely frost-evap sensor faulty.
no frost on evap-check evap cover.this can retain water causing it to ice up around fan.Defrost cover and under the fan motor there is a channel.make the hole larger to stop it retaining water.It needs to defrosted thorghly to remove any ice in channels of cover.

Superfly I think you hit the nail on the head 100%
the only thing i would add is
sometimes the insulation panel becomes water logged
& either needs replacing or Put in a Vacume chamber to remove all the moisture from it..otherwise it can keep freezing & you will still geta ice build up on it

[paul_h]

damn it, I lost it all, how can you cut and paste in the reply box?
I've been repairing these fridges for four years and know everything about them.
faults are:
thermal fuse
open circuit heater
These fault give a flashing or incorrect temp read out.
replace the thermal fuse if getting bad temp display even if it tests ok (it fails under current flow)

coil sensor
this tells the fridge if it should defrost, and when to terminate. It's the bottom plug yellow lead. check DC volts, it should be greater than 2v more like 3v on an iced up fridge. at 2v it thinks it's higher than 0 celcius so defrost wont happen. It's a good idea to unplug the sensor and check if there's 5Vdc at the actual plug, making sure the PCB is sending out the right voltage

evap insulation gets water logged and iced up. stops the fan turning. symptoms will be a reasonbly ice free coil but a fully iced up fan.

edit: by the way none of the older samsungs (the first of the twin cools) had this problem.
The faulty sensors only started happening in large numbers with the cheaper side by side single evap models. Earlier coil deforst sensors were ok too (but the thermal fuse fault was common)
Also the iced up evap insulation only started to happen to fridges made ~2 years ago.
So most of the four year old+ fridges didn't have the most common problems around today.

[duarte]

Try to see near the compressor if it exists there a defrost tymer. If it is there, test it and see if it start the defrost resystors.

[paul_h]

Try to see near the compressor if it exists there a defrost tymer. If it is there, test it and see if it start the defrost resystors.
Thats for the models with freezer on top, ie the old style which are the cheaper ones. Any fridge which is side by side or has digital controllers won't have a mechanical defrost timer down near the compressor.