Roper Refrigerator Back Panel Icing Up: Troubleshooting... | appliancefaults.com

Technical Background:

The refrigerator's Main Control Unit (MCU) manages the defrost cycle, which melts frost buildup. The MCU sends 120V AC to the defrost heater via the defrost thermostat. The thermostat acts as a safety device, preventing overheating. The thermistor sends temperature readings back to the MCU.

Symptoms:

The homeowner notices thick frost or ice accumulation on the back panel inside the freezer compartment of their Roper refrigerator. The refrigerator may not be cooling efficiently, and food may be spoiling.

Possible Causes:

Defective defrost heater
Faulty defrost thermostat (bi-metal switch)
Failed defrost timer (or electronic control board)
Damaged door seal allowing warm, moist air to enter
Blocked defrost drain
Defective thermistor

Solution:

1

Unplug the refrigerator from the 120V AC outlet.
2

Remove the back panel inside the freezer using a 1/4-inch nut driver.
3

Inspect the defrost heater for continuity using a multimeter. A reading of OL (open line) indicates a failed heater. Replace if defective.
4

Test the defrost thermostat for continuity. It should be closed (showing continuity) when cold (below approximately 40°F). If open when cold, replace the thermostat.
5

Check the defrost drain for blockage. Use hot water or a flexible wire to clear any obstructions.
6

If the heater, thermostat, and drain are clear, suspect a faulty defrost timer or electronic control board. If equipped with a defrost timer, manually advance the timer into defrost and check if the heater activates. If not, replace the timer.
7

If equipped with an electronic control board, it may require replacement by a qualified technician. Consider a service call from a NASTeC certified technician.

Safety Warning:

Always disconnect power (LOTO - Lock Out Tag Out) to the refrigerator before performing any repairs. Electrical shock hazard exists when working with 120V AC components. If you are not comfortable working with electricity, contact a qualified appliance repair technician.

Prevention:

Regularly clean the refrigerator door seal with warm, soapy water. Ensure the refrigerator is level to ensure a proper door seal. Periodically check the defrost drain for blockage.

Expert Tip:

Many Roper refrigerators have a forced defrost cycle activated by pressing and holding the freezer temperature DOWN button and the refrigerator temperature UP button simultaneously for 5-10 seconds. This can help diagnose defrost system issues.

Frequently Asked Questions

•How do I access the defrost timer on my Roper refrigerator?

The defrost timer is typically located behind the kick plate at the bottom front of the refrigerator or behind the control panel inside the refrigerator. You may need to remove screws or clips to access it.

•What is the best way to clear a clogged defrost drain?

The most effective method is to use a turkey baster or syringe to flush hot water down the drain. You can also use a flexible wire, such as a weed trimmer line, to carefully dislodge any debris.

•How do I test the thermistor in my refrigerator?

You'll need a multimeter and a temperature chart for your specific Roper model. The thermistor's resistance changes with temperature. Compare the resistance reading at a known temperature to the chart to determine if it's within the correct range.

Roper Refrigerator Back Panel Icing Up: Troubleshooting & Repair Guide

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip:

Frequently Asked Questions

•How do I access the defrost timer on my Roper refrigerator?

•What is the best way to clear a clogged defrost drain?

•How do I test the thermistor in my refrigerator?

Related questions

Technical Background:

Symptoms:

Possible Causes:

Solution:

Safety Warning:

Prevention:

Expert Tip: