For test 4, I used an infrared thermometer and for segment 01 where the valve is initialized I got 1.9 degrees in the freezer and 33 degrees at the fridge evap coils that you can see at the bottom.
For segment 02 and 03 no real temp change, I got 6 degrees in the freezer and 33 degrees at the fridge coil.
For segment 04, I got a decrease in the freezer down to -0.7 degrees and a rise in the refrigerator coil to 38 degrees
For segment 05, The freezer was at 5 degrees and the refrigerator coil was at 22 degrees.
Because I was opening the doors to measure temp with the IR thermometer, I repeated the test with a thermistor probe in the refrigerator evap coil and kept the door closed so as not to let warm air in skewing results and I got the following for test 4:
Step 01 - 33 degrees
Step 02 - 33 degrees
Step 03 - 33 degrees
Step 04 - started at 33 degrees, then dropped to 27 degrees
Step 05 - started at 27 degrees and kept dropping down to 18 degrees
After getting out of Test 4, temp came back up to 33 degrees.
Step 05 is the only one that I thought was strange, as the fridge evap coil kept dropping in temp until I ended the test.
I'm not sure how to interpret the readings I got. It appeared to function like it should steps 1-4 but it was strange on step 5, where the refrigerator evap coil temp kept dropping. Either there was some residual pressure getting through the expansion valve and dropping the coil temp since the fan stopped running on the fridge side (as per the test), or the valve keeps sending refrigerant to the fridge side when it is supposed to be going to the freezer only. I just want to be sure that replacing the control board will fix my problem.
I just located a service bulletin on this issue, but we need the serial number of yours.
SERIAL NUMBERS: Prior to HRX40
In certain circumstances, consumers may experience warmer than usual temperatures in the refrigerator section, due to ice accumulation on the evaporator.
This concern can result from multiple possible causes including:
● Failed or restricted evaporator fan motor
● Faulty or mislocated defrost thermistor
● Poor door gasket sealing
● RC door not closing properly
● Air leaks within the air duct, and evaporator cover assembly.
● Evaporator fan not running long enough to clear frost.
● Verify Proper operation of evaporator fan motor
● Verify proper placement of defrost thermistor
● Correct any door sealing issues
● Ensure there are no obstructions preventing the RC door from closing properly
● Verify Proper door alignment
● Install the evaporator cover correctly
If you have checked and ruled out the other possibilities listed above, then follow the steps below to correct the issue.
Inspect assembly of airflow parts, and correct as needed.
NOTE: If the evaporator cover is difficult to reassemble, this may indicate that airflow parts are not properly aligned and not sealing properly. Realign the evaporator cover for proper installation.
Refer to the table below and replace the HMI/User interface accordingly. The new HMI/UI extends the run time of the evaporator fan to assist with the prevention of excessive frost build up.