dt
Whirlpool Refrigerator
Severity: ModerateWhat Does This Error Mean?
The dt error means your Whirlpool refrigerator has detected a problem with the defrost system. Refrigerators automatically defrost the evaporator coils on a regular cycle. If this defrost cycle does not complete correctly, frost builds up on the coils and the refrigerator loses cooling ability.
Affected Models
- WRF535SWHZ
- WRS325SDHZ
- WRB322DMBM
- WRF767SDHZ
- Most Whirlpool frost-free refrigerators
Common Causes
- The defrost heater has burned out and is no longer melting frost from the evaporator coils
- The defrost thermostat (bimetal thermostat) has failed and is not allowing the heater to activate
- The defrost timer or control board is not initiating defrost cycles at the correct intervals
- The evaporator coils are heavily iced over due to a prolonged defrost system failure
- The defrost sensor (thermistor) is reading incorrectly and cutting the defrost cycle short
How to Fix It
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Unplug the refrigerator for 24–48 hours with the doors open to manually defrost it.
Place towels on the floor to catch water. This can temporarily restore cooling if iced-over coils are the only problem.
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After manual defrost, plug the refrigerator back in and monitor whether the error returns.
If the error returns within a few days, the defrost heater or thermostat has failed and needs replacement.
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Locate the defrost heater — it wraps around the evaporator coil inside the freezer compartment behind the rear panel.
You'll need to remove all freezer shelves and the back panel to access it.
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Test the defrost heater with a multimeter for continuity.
No continuity means the heater element is broken and needs replacement.
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Also test the defrost thermostat with a multimeter.
At room temperature, the thermostat should have continuity (closed). If it reads open at room temperature, it has failed and needs replacement.
When to Call a Professional
Defrost system repairs require accessing the evaporator coils inside the freezer wall. This involves removing shelves, panels, and possibly significant frost buildup. If you are not comfortable with this level of disassembly, a technician is the right choice. Defrost heater kits typically cost $30–$80.
Frequently Asked Questions
How do I know if my refrigerator's defrost system has failed?
The most common sign is ice buildup on the freezer's back wall or poor cooling in the fresh food section. If you pull the freezer's back panel and find a solid block of ice covering the evaporator coils, the defrost system has failed. The dt error code confirms this electronically.
How often should a refrigerator run a defrost cycle?
Most frost-free refrigerators run a defrost cycle every 8–12 hours. The cycle lasts about 20–30 minutes. You usually cannot hear or notice it happening — it is automatic and silent.
Can I prevent the dt error from happening again?
Not entirely, as defrost components wear out over time. Avoiding leaving the refrigerator door open for long periods reduces the frequency of defrost cycles needed. Replacing the defrost heater and thermostat together (even if only one has failed) is good practice — they are cheap and you're already in there.