Samsung Refrigerator 40C Error Code: Ice Maker Room Temp Sensor Fix

Quick Answer

Samsung 40C is an ice maker room ambient temperature sensor fault specific to French door and 4-door Flex models (RF23, RF28M series) where the ice maker sits in a dedicated compartment with its own temperature management.

The Samsung 4-door Flex context is important: on Flex models, the 40x code range also covers the flex zone drawer temperature sensor circuit, so 40C on a 4-door Flex may point to either the ice room sensor or the flex zone ambient sensor - service mode is needed to differentiate. Samsung French door models built between 2014 and 2019 have a documented pattern where the ice room sensor fails as a secondary consequence of the ice room freeze-over issue (the same root cause as 33E), because sustained ice buildup in the compartment eventually damages the sensor wiring. If a Samsung refrigerator shows both 33E and 40C in the error history, the ice room door gasket failure is almost certainly the common root cause for both codes.

SamsungRefrigeratorSeverity: mediumDifficulty: intermediate76% DIY Success

Time to Fix

30–75 min

Difficulty

intermediate

Parts Cost

$10 – $160

Tools Needed

Multimeter (ohm mode), Phillips screwdriver

What Does the 40C Code Mean?

The ice maker room ambient temperature sensor has failed. On 4-door Flex models, 40C may also indicate a flex zone sensor fault. Check service mode to identify the specific sensor circuit.

Most Likely Causes

Based on aggregated repair data, here is the probability breakdown for this error code:

Ice maker room ambient temperature sensor failure40%

Ice room freeze-over damaging sensor or wiring (linked to gasket failure)24%

Flex zone drawer sensor fault on 4-door Flex models (same code range)22%

Sensor connector corroded from ice room moisture14%

Symptoms You May Notice

40C displayed on Samsung refrigerator panel
Ice maker not producing ice or producing less than normal
40C may appear alongside 33E (ice room freeze-over pattern)
Ice room compartment temperature display abnormal or missing

Can you reset a Samsung refrigerator to clear the 40C code?

Press any panel button to dismiss 40C. Unplug for 5 minutes after sensor replacement. Restore power and enter service mode to confirm the ice room sensor shows a plausible temperature reading.

Tools Required for Diagnosis

Multimeter (ohm mode)Phillips screwdriverNut driver (1/4")Hair dryer (if ice room needs thawing)FlashlightTowels

Diagnostic Checklist

Follow these steps in order. We start with the easiest external fixes before opening up the machine.

Enter service mode

Enter service mode: hold Energy Saver and Fridge buttons for 8 seconds. Check ice room sensor reading and note if any other codes are stored (especially 33E). On 4-door Flex models, check if the flex zone sensor circuit is also showing an error.

Open the ice maker compartment and inspect for ice buildup

With the refrigerator unplugged and ice room clear

Replacement Parts

If your diagnostic testing proves the component has failed, you will need a replacement. We recommend OEM parts over aftermarket for water-handling components.

Part Name	OEM Number	Estimated Price
Samsung Ice Room Ambient SensorDA32-00006W · $10–$25	DA32-00006W	$10 – $25
Samsung Ice Room Door GasketDA97-12540A · $10–$20	DA97-12540A	$10 – $20
Samsung Ice Maker AssemblyDA97-15217D · $80–$160	DA97-15217D	$80 – $160

Verify part fitment for your Samsung model

Repair vs. Replace Calculator

Appliance Age (Years)7 Yrs

Labor Approach

Our Verdict

REPAIR

Estimated Cost: $85 (Parts) vs $2850 (New Machine)

Frequently Asked Questions

What is the difference between Samsung 40C and 40E?

40E is the ice maker cycle temperature sensor - it monitors the temperature during the ice making process itself (tray filling, freezing, harvest cycle). 40C is the ice room ambient temperature sensor - it monitors the air temperature inside the ice maker compartment. They are different sensors in different locations within the ice maker assembly.

Can Samsung 40C appear on a 4-door Flex refrigerator for a different reason?

Yes. On Samsung 4-door Flex models (RF23, RF28M series), the 40x code range covers both the ice maker sensor circuit and the flex zone drawer temperature sensor circuit. If 40C appears on a 4-door Flex, service mode is needed to determine whether the fault is in the ice room or the flex zone. The two circuits require different sensor parts.

Should I replace the ice room gasket even if 40C is the only code?

Check the gasket regardless. The ice room freeze-over pattern that causes 33E and 40C together starts with the gasket failing silently before the fan (33E) and sensor (40C) codes appear. If the ice room shows any signs of heavy frost accumulation or if the gasket has any softness or gaps, replace it alongside the sensor. The $15 gasket replacement prevents future freeze-over events.

Related Samsung Refrigerator Error Codes

Code: HUBSamsung Refrigerator Error Codes: 39C, 33E, 40E and More Code: 33ESamsung Refrigerator 33E: Ice Maker Fan Motor Fault Code: 40ESamsung Refrigerator 40E: Ice Maker Sensor Fault Code: 39CSamsung Refrigerator 39C: Freezer Defrost Sensor Fault

Same Fix Works on These Brands

Samsung shares the same hardware platform with these brands. The diagnosis and repair steps are identical.

Samsung washerSamsung Washer 3C2 Error Code: Motor Stall Samsung washerSamsung Washer 3E Error Code: Motor Fault Samsung washerSamsung Washer 4C Error Code: No Water Supply Samsung washerSamsung Washer 4E Error Code: Water Supply Fault (Top Load)Samsung washerSamsung Washer 5C Error Code: Drain Error (Older Display)Samsung washerSamsung Washer 8C Error Code: Vibration Sensor Fault

Models Known to Experience 40C Errors

This repair applies to most Samsung refrigerators with this error code. Common model numbers include:

RF28R7351SR, RF23M8070SR, RF23HTEDBSR, RF28HMEDBSR, RF28K9070SR

Last verified for technical accuracy on March 14, 2026