LG Dishwasher HE — What It Means & How to Fix It

The dishwasher's water heating system isn't working as expected — and because it involves a high-wattage heater on mains power, this is one to hand to a technician.

What this code means

HE indicates a heating error: the water temperature didn't rise the way the control board expected during the wash, or the thermistor reported readings outside the plausible range. The heating element, its relay on the control board, or the temperature sensor are the usual suspects — all of them mains-voltage components buried in the base of the machine.

HE relates to water heating on LG dishwashers. A power reset is worth one attempt in case it's a control glitch, but a recurring HE is a hardware fault, not something a setting change fixes.

Most likely causes

CauseHow likelyDIY-fixable?
Failed heating element Common No — technician job
Faulty thermistor (temperature sensor) Common No — technician job
Heater relay or control board fault Occasional No — technician job
One-off control glitch after a power event Occasional Yes — power reset only

What you can try yourself

  1. Turn the unit off at the breaker, wait two minutes, and restore power. If HE was a one-time control glitch, a fresh cycle will run normally.
  2. Confirm your hot water supply is working at the kitchen tap — extremely cold inlet water can stretch heating beyond the time the board allows on some cycles.
  3. If the code returns, stop using the dishwasher and book a repair. The remaining suspects all live on mains wiring in the base of the unit.
  4. Note for the technician which cycle the error appears on and whether dishes have been coming out cold and wet recently — that history shortens the diagnosis.

When to call a technician

Typical professional repair cost: Heating element replacement typically runs $150–$300 with labor; a thermistor swap is usually somewhat less. A control board replacement can reach $250–$400.

Frequently asked questions

Why can't I replace the dishwasher heating element myself?

The element is a high-wattage component on mains voltage, sealed into the sump under the tub. Reaching it means disconnecting and tipping the unit, and an imperfect reinstall risks both leaks and electrical hazards. This combination is firmly technician territory.

Will the dishwasher still wash with an HE code?

Some models block the cycle entirely; others may limp through with cold water. Either way you'll get poor cleaning and no proper drying, and you're running a machine with a known electrical fault — better to wait for the repair.

Could the HE error just be my home's hot water being off?

Cold supply alone usually doesn't trigger HE — the machine heats internally. But a cold inlet plus a marginal element can tip a long cycle over the time limit. Restoring your hot water and retrying once is reasonable before booking the visit.

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