What this error means
Heating fault — the dishwasher is not reaching the correct wash temperature
The HC error means the dishwasher has failed to heat the water to the required temperature within the allowed time, or the temperature sensor has returned an out-of-range reading. The most common causes are a failed heating element, a faulty NTC thermistor sensor, or heavy limescale build-up on the element insulating it from the water. A wiring fault to either component can also produce this code.
What you'll need first
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Step-by-step
Symptoms to look for
- Dishes coming out cold, greasy, or with undissolved detergent residue
- Interior of the dishwasher feels no warmer than room temperature during a hot programme
- HC displayed partway through a wash or rinse programme
- Programme runs significantly longer than the displayed time before faulting
Diagnostic steps
Unplug for 5 minutes to reset the board. Plug back in and run the hottest available programme — Intensive or 70 degrees — with no load. After 15 minutes, carefully and briefly open the door a few centimetres. You should immediately feel warm to hot steam escaping. If the interior feels no warmer than room temperature, the element is not heating at all.
Add a proprietary dishwasher descaler or two tablespoons of citric acid to the base of the tub and run a full 65-degree empty cycle. On Samsung dishwashers the heating element can accumulate a thick layer of limescale that acts as insulation — the element draws full power but transfers very little heat to the water. This is the most common cause of gradual heating performance loss before HC appears.
Open the salt cap on the floor of the dishwasher tub. If the reservoir is empty or very low, top it up with coarse dishwasher salt (not table salt). The built-in water softener uses this salt to prevent limescale from forming on the element and spray arms. Running without salt in a hard water area causes accelerated scaling and eventual heating failure.
With the dishwasher completely unplugged, remove the lower basket. The heating element is the U-shaped or circular metal bar running across or around the base of the tub. Inspect it for cracks, orange corrosion patches, or areas where the coating has burnt away.
With the dishwasher unplugged, remove the lower kickplate panel. The element terminals protrude through the base of the tub and are accessible from underneath. Disconnect the wiring from both terminals and test across them with a multimeter set to resistance. A healthy Samsung dishwasher element typically reads between 20 and 30 ohms. A reading of zero (short circuit) or OL (open circuit) means the element has failed.
The NTC sensor is mounted in the sump area or near the base of the tub, connected by two thin wires. Disconnect its connector and test across the terminals with a multimeter. At room temperature a healthy Samsung dishwasher NTC typically reads between 4,000 and 12,000 ohms. A zero or OL reading indicates the sensor has failed.
When to call an engineer
- Heating element reads outside 20 to 30 ohms or shows continuity to earth — must be replaced
- NTC thermistor reads open circuit or zero on a multimeter
- Element tests within normal range but HC persists — wiring or control board fault
- Visible orange corrosion, cracking, or burnt sections on the element surface in the tub base
Frequently asked questions
What is the NTC thermistor and why does it cause HC?
Can limescale alone cause HC without the element being broken?
Are dishes safe after a cycle that triggered HC?
How do I know whether it is the element or the thermistor that has failed?
🎯 What is likely causing this fault?
⚠️ Estimates based on common faults — not a guaranteed diagnosis. Always verify before ordering parts.
Parts you may need
Enter your model number to filter results to your exact machine
Usually found on a label inside the door frame or on the back panel of the machine.
| Part | Approx. UK Cost | Find it |
|---|---|---|
| Heating Element | £40 - £60 | 🏷️ eBay UK → |
ℹ️ Prices are approximate. Always check the part number matches your model before ordering. Not sure of your model number? Find out how to locate it here.