Samsung RF4287HA** freezer not cold

[HapppyDad]

Started out with your majesty complaining that freezer is not cold.  Diagnostic error displayed 5E code, which is the fresh food(FF) defrost sensor problem.  Threw me a curve ball because I thought fixing the FF defrost sensor will fix the freezer problem because this model is supposed to be 'twin cooling' meaning dual evaporators with separate refrigerant lines.  Unfortunately, replacing the sensor and getting rid of the error code did not keep the freezer cold.  There's hardly any ice on either evaporators.

I eventually broke down and attached a piercing valve to check pressure.  The low-side pressure when unplugged was around 40psi.  When the compressor is running, it dropped to 10psi.  Shouldn't the low-side pressure be around 0psi?  I suspect either a 3-way step valve malfunctioning, or a restriction in the freezer capillary tube according to the service manual showing the two routes that refrigerant can take place:

1. Compressor → Condenser → Hot Pipe → Back Cluster Pipe → Dryer → Ref Capillary Tube → Refrigerator Evaporator → Freezer Evaporator → Suction Pipe → Compressor

2. Compressor → Condenser → Hot Pipe → Back Cluster Pipe → Dryer → Fre Capillary Tube → Freezer Evaporator → Suction Pipe → Compressor

To my astonishment, I found the 3-way step valve missing, and the electrical wiring connections to the controller board empty, i.e. no pin connections to the connector on the pcb board.  According to the service manual diagram, the valve would be located right after the dryer, and actually control the flow of refrigerant between the refrigerator or the freezer tube.  Since that is evidently missing, what do you think is happening to the actual connection?  Do you think there's an actual parallel connection from the dryer to both refrigerator and freezer tubes?  (Notice that the refrigerator route eventually joins up to the freezer evaporator to complete the system).  

Your majesty says ice cream was cold for almost 5 years, so must be working well.  I am now stumped as to how the separate temperature control can be achieved when the lines are shared.  How do I fix this?  Very tempted to put more R134A but isn't 10ps on the low-pressure side a little on the high side?  Thanks in advance.

 

[Quick]

22 minutes ago, HapppyDad said:

To my astonishment, I found the 3-way step valve missing

Perhaps you're looking at the wrong service manual? You have a slave system. No 3 way valve to it.

 

 

[HapppyDad]

Here's the service manual, pages 19-21:

http://www.msaworld.com/wp-content/uploads/sites/3/2015/03/RF4287HA-Service-Manual.pdf

Why are you certain I have a slave system?  Perhaps they decided the 3-way valve is not needed to save cost?

[Quick]

 

27 minutes ago, HapppyDad said:

Why are you certain I have a slave system?  Perhaps they decided the 3-way valve is not needed to save cost?

Because it just don't work that way.

Post the complete Model Number.

Gotta be a manual mix up.

 

 

 

 

[HapppyDad]

The full model number is RF4287HABP.  My guess for the missing 3-way valve is that Samsung decided to not incorporate it and default to the slave system.  The claim of 'twin-cooling' still holds because that is controlled by fans for the different compartments.  

BTW, with the 5E code FF-Defrost sensor error on, the temperature readout for the refrigerator and freezer is garbage.  It shows the temperature slowly getting down to the set temperature, i.e. freezer temperature displays as eventually getting down to -2F, but an actual thermometer in the freezer only registers around 38F.  After changing out the FF-Defrost sensor, both temperature readouts from the display appears to be correct to within 2F.  But the freezer now hardly cools at all.  Was ~50F yesterday and this morning was 70F.  

Right after the wife mentioned the cooling problem, I did find a lot of dust surrounding the condenser.  So I thought cleaning out would solve the problem.  She also noticed that the compressor was noticeably louder, like when it starts up, it makes this louder than usual rattling sound before getting quieter.  Do you guys think this may be a compressor problem from the lack of ventillation causing it to heat up more than it should, and over time, weakening it's power and causing the low-side suction pressure to read higher psi than it should?  The refrigerator did take quite a bit of time (I would say about 4 hours) to finally reach the set 38F temperature, and I was wondering if the defect in the condenser might have caused the refrigerant flow rate to be compromised, and thus not cooling down low enough?

[16345Ed]

Did you test all sensors?

anyone of the sensors failing can cause trouble. 

Test for resistance and under load. 

[HapppyDad]

I did test all the low-voltage sensors, and they checked out about right, meaning at room temperature, the thermistors are around 5kohms.  If any sensors are failing, I would think that the control board would throw a code.  Again, no frost that I can tell, defrost heater is working (drip pan does get wet), refrigerator does get to temperature if it sits for a while.  Freezer still sits at 60-70F.  Compressor makes a louder rattling noise at startup before getting quieter, and believe it or not, it does shut itself off.  And the shutoff temperature at the compressor wasn't unbearable, maybe 100F.  Why is it shutting off, that I don't know.  I don't think 100F will trigger the thermo switch.

[16345Ed]

2 minutes ago, HapppyDad said:

  If any sensors are failing, I would think that the control board would throw a code. 

This statement could not be more wrong. 

 

[Lighthouse]

Sensor is probably Samsung most common failure & few of those throw a code. They are too cheap & too common of a problem not to just change them out.

Edited July 13, 2018 by Lighthouse
added info