[cshipman]

The refrigerator side of my Samsung RS253BASB/XAA does not get cold. The evaporator coil is iced up, as in a solid block of ice. It's a well known issue with this model, but Samsung disavows any knowledge of it. The unit is no longer under warranty. Samsung wants to send a repair person from out-of-town to fix it and charge me an arm and a leg.

I checked the basics first: the door seals are good and tight and the condensate drain is not obstructed.
I removed the covers and I viewed the symptom I have described. I believe that I have the issue narrowed down to 4 parts: the temperature sensors (there are two), the fixer sensor (thermistor?), and the the water heater. Presumably the water heater is supposed to prevent the coil from icing. There is continuity and some resistance across the water heater, so I don't think it is the culprit.

I'm a fairly bright person, a field service engineer for desktop and laptop computers, laser printers, LCD and plasma TV's, etc. I am mechanically and technically capable of replacing the parts I have mentioned and I have no doubt that I can fix this damn refrigerator myself if I just knew which part to replace.

A parts list and diagram for this unit can be seen at: Model RS253BASB

Any ideas or advice? Your guidance will be appreciated!

Craig

[smoothieking]

Hey cshipman, I had this happen to me 2 years ago and just now again. Back then I purchased a Part number: DA47-10160H

and Part number: DA32-0006W

and will do the same now adding a Part number: DA47-00095E

this time.

[cshipman]

Thanks for the response smoothieking. I think I fixed the stupid thing on July 4.

There was no continuity across the defrost heater terminals, so I knew the heater was bad. Here's what I did:

1. Remove the topmost 2 drawers.

2. Defrost the evaporator coil thoroughly. If ice is present, the removal of the covers is very difficult.

3. Remove the 2 screws that hold the water chiller in place and lay the water chiller on top of the bottom most drawer.

4. Remove the back covers from the middle down. There are about 7 or 9 screws and two electrical lead wire connectors to remove.

5. Two pop rivets hold the bottom of the heater coil to a piece of sheet metal. One rivet holds the right side. It is necessary to remove the one on the right. I removed all three and I believe it made removal of the heater coil much easier. I used a small pair of wire cutters to do this. I did not replace any pop rivets.

6. Remove the cable ties that secure the wires and thermostats to the evaporator assembly.

7. Carefully release the defrost heater from the evaporator coil by gently bending the fin tabs that hold it in place with a pair of needle-nose pliers.

8. Carefully and gently work the defrost heater out of the evaporator assembly by pulling the whole assembly a few inches away from the back of the refrigerator and sliding the defrost heater to the right.

9. Pick one end of the heater coil and slide the black rubber cap off of the end of the heater tubing and up the electrical lead wire. I found my problem occurred on the end with the white electrical lead wire.

10. Carefully cut only the crimped tubing from one end of the heater coil taking care not to damage the insulated thermoelectric braid inside. I used a small pair of wire cutters to do this.

11. Split the crimped aluminum tubing to free the gray rubber plug. I used a small pair of wire cutters to do this. Slide the plug up the electrical lead wire (a little spit helps it slide easier).

12. Inspect the crimped connection of the insulated thermoelectric braid and electrical lead wire. If the connection is firm, follow steps 9 through 12 on the other end of the heater coil.

13. If you are lucky, as I was, you will find a broken crimp connection at one end or the other. If you do, carefully cut and strip both the insulated thermoelectric braid and electrical lead wire and reconnect them with a crimp connector that will fit inside of the gray rubber plug.

14. Test the resistance of the heater circuit. Mine showed resistance of 99 ohms after the repair.

15. Carefully cut the gray rubber plug off to fit the shortened length of tubing.

16. Carefully push the crimped connection into the gray rubber plug.

17. Carefully push the gray rubber plug into the heater tubing. It helps if there are no burrs on the edges of the tubing.

18. Make the seal between the rubber plug and the tubing watertight. I used hot glue.


19. Slide the black cap down over the rubber plug.

20. Test the resistance of the heater circuit again just for good luck.

21. Carefully work the defrost heater and sheet metal back into position. Bend the metal tabs gently to hold it in place.

22. Test the resistance of the heater circuit again just for good luck.

23. Secure the wires, thermostats and coils neatly with cable ties and make sure the three electrical lead wire connectors are plugged in.

24. Replace the rear covers and make sure the two electrical lead wire connectors are plugged.

25. Replace the water chiller.

25. Replace the drawers.

26. Plug the refrigerator in.

Good Luck!

[smoothieking]

Wow - now those are some detailed instructions!

On that detailed diagram, on which number do I test the ohm resistance? #11? And where exactly should I place the two testing points?

Thanks!

[cshipman]

Sorry for the omission. You definitely want to test the resistance of the defrost heater before going to the trouble of completely removing it. If resistance is within the range of 75-125 ohms the defrost heater is good and the problem is somewhere else. The thermostats could also be tested but I didn't need to, so I didn't. I don't know what the expected readings should be or for what temperature.

The connectors for the defrost heater and thermostats are exposed after removing the back cover (step 4). The connector for the defrost heater has one red and one white wire going to it. Unplug this connector and test for resistance across the terminals. From what I've read, resistance should be in the range of 75-125 ohms.

[cshipman]

I also found these webpages to be helpful in making the decision to tackle this repair myself:
Samsung Refrigerator Heater Repair - RN's site

[smoothieking]

Fantastic - thanks so much!