Samsung Dishwasher Error Code HC — What It Means & How to Fix It

What Does This Error Mean?

The HC error on a Samsung dishwasher means the water temperature is too high — the machine detected water that is hotter than it should be. Samsung dishwashers expect incoming water to be warm, not scalding. If your home's hot water supply is set above 158°F (70°C), the dishwasher's thermistor can flag an overheat condition and display HC. This protects internal components and your dishes from heat damage. It is different from the HE error, which means the heater is not working — HC means the opposite: too much heat.

Affected Models

Samsung DW80R9950UG
Samsung DW80T5430US
Samsung DW80CG5451SR
Samsung DW80K5050US
Samsung DW80J3020US

Common Causes

Home water heater set too high — above 158 degrees Fahrenheit causes HC on many Samsung models
Faulty thermistor (temperature sensor) reading the water temperature incorrectly and reporting it as too high
Control board malfunction sending the wrong signal to the thermistor circuit
Recent plumbing work that changed the hot water supply pressure or temperature to the dishwasher
A stuck or failing water inlet valve allowing extremely hot water to continue entering the tub

How to Fix It

Check your home's water heater temperature. Go to your water heater and look for the temperature dial or display. The recommended setting for dishwashers is 120°F (49°C). If yours is set significantly higher — especially above 140°F — lower it to 120°F and wait an hour for the water in the pipes to cool down.

Lowering the water heater temperature is safe and actually saves energy. The dishwasher's internal heater boosts water temperature during the cycle as needed.
Run the hot water in your kitchen sink for 60 seconds before starting the dishwasher. This flushes out any super-hot water sitting in the pipes near the water heater. Then start a new cycle and see if HC appears.

Water sitting in pipes next to a water heater can get hotter than the heater's set temperature. Flushing it first gives the dishwasher cooler incoming water.
Reset the dishwasher by pressing and holding the Start/Cancel button for 3 seconds, or unplugging the machine from power for 5 minutes. Restore power and run a quick wash cycle to see if HC returns after you have adjusted the water temperature.

A power reset clears any error flags stored in the control board's memory. Always do this after fixing the root cause.
If HC returns despite a correct water heater temperature, the thermistor may be faulty. The thermistor is usually located inside the sump assembly at the bottom of the tub. A working thermistor should measure resistance that changes predictably with water temperature — flat or erratic readings indicate failure.

Thermistor testing requires a multimeter and some comfort with appliance disassembly. If you are not confident, call a technician.
If the thermistor tests fine, suspect the main control board. A control board sending wrong voltage to the thermistor circuit will cause incorrect temperature readings even when the sensor is good. At this stage, schedule a Samsung-authorized technician — board diagnosis requires specialized tools.

Before agreeing to a control board replacement, ask the technician to confirm the thermistor and wiring are definitely not the cause.

When to Call a Professional

If lowering your water heater temperature does not clear HC, a technician is needed. Testing the thermistor requires a multimeter and accessing internal components. Thermistor replacement typically costs $75-$130 including parts and labor. Control board replacement costs $200-$400. Always rule out the water heater setting first — it is free to check.

Frequently Asked Questions

Is HC dangerous — can it start a fire or damage my kitchen?

No — HC is a protective error, not a dangerous failure. The dishwasher detects water that is too hot and stops the cycle to prevent damage. It is actually a safety feature working correctly. The risk, if any, is the very hot water coming from your home supply — which is a burn hazard at your sink too, not just in the dishwasher.

What temperature should my water heater be set to?

The U.S. Department of Energy recommends 120°F (49°C) for most homes. This is hot enough for cleaning and sanitation but safe for dishwashers and reduces the scalding risk at taps. Some dishwasher manuals suggest 120-140°F as acceptable. Above 140°F is when Samsung dishwashers commonly trigger the HC error.

Will HC come back after I fix it?

If you corrected the root cause — usually the water heater temperature — HC should not return. If it keeps coming back even with the water heater at 120°F, a faulty thermistor is likely reading temperatures incorrectly. In that case the sensor needs to be replaced, not just the settings adjusted.