LG Dishwasher Error Code HE2 — Heater Relay Error

What Does This Error Mean?

The HE2 error means there's a problem with the heater relay on your LG dishwasher's control board. The heater relay is an electrical switch on the control board that turns the heating element on and off. When this relay fails or the control board detects an unexpected signal from it, HE2 appears. Your dishes may not get fully clean or sanitized because the water won't reach proper washing temperature. HE2 often requires a control board replacement.

Affected Models

LDF5545ST
LDT5678SS
LDFN4542S
LDT7808SS
LDP6810SS
Most LG dishwashers with electric heating element

Common Causes

Failed heater relay on the main control board — the relay burned out or became stuck
Heating element has shorted and overloaded the relay, causing it to fail
Wiring between the control board and the heating element has a short or open circuit
Temperature sensor (thermistor) reporting incorrect temperatures causing the board to flag a relay error
Power surge that damaged the relay circuitry on the control board

How to Fix It

Unplug the dishwasher for 10 minutes and plug it back in. Run a short wash cycle and see if HE2 returns. Power resets can sometimes clear a stuck relay condition if the failure is not permanent.

If HE2 disappears after a reset but returns after several cycles, the relay is on its way out and will need replacement soon.
Check your wash results. If dishes are coming out with food still stuck on, or the water feels cool when you open the door mid-cycle, that confirms the heating element or its relay is not working. Cold wash water is a strong indicator of a heater-related failure.

Normal wash water should be hot enough that steam rises briefly when you open the door at the end of a hot cycle.
Test the heating element with a multimeter if you're comfortable doing so. Disconnect the dishwasher from power. Access the element (usually accessible from inside the tub by removing the lower spray arm and filter). Disconnect the wiring and test resistance across the element terminals — it should read 20-30 ohms for a working element. Infinite resistance means the element has failed open.

A failed heating element causes the relay to behave abnormally, often triggering HE2 even when the relay itself is fine.
If the heating element tests fine, the control board's heater relay has failed. This typically means the entire main control board needs replacement. On most LG dishwashers, the main board is located in a panel at the bottom front of the machine, accessible by removing the kick plate.

Unless you have soldering skills, relay-level repair of the board isn't practical. Replacing the whole board is the standard fix.
After replacing the faulty component, run three consecutive cycles and monitor for HE2 return. If the error doesn't come back, the repair is successful. If it returns immediately after replacing the board, suspect the heating element is shorted and replacing both may be necessary.

A shorted heating element will damage a new control board if not also replaced. Test the element before installing a new board.

When to Call a Professional

HE2 almost always requires replacing either the control board or the heating element — sometimes both. Replacement control boards for LG dishwashers cost $80-$180. A heating element costs $25-$60. Diagnosing which component failed requires testing with a multimeter. A technician charges $150-$320 for this type of repair.

Frequently Asked Questions

What's the difference between HE and HE2 on LG dishwashers?

HE usually means the heating element itself has failed or isn't reaching target temperature. HE2 is more specific — it points to the heater relay circuit on the control board. In practice the fixes overlap: test the heating element first, then the control board. Sometimes both components fail together.

Can I still wash dishes with HE2 active?

The dishwasher may still run through cycles, but washing effectiveness will be poor without heat. Dishwasher detergents are designed to work best with hot water. Cold water cycles leave grease and bacteria on dishes. Use the dishwasher sparingly and only for lightly soiled loads until the repair is done.

Does HE2 mean my dishwasher isn't sanitizing dishes?

Correct — without a working heater, the sanitize cycle and high-temperature wash options don't actually sanitize. If you're washing baby bottles, cutting boards used for raw meat, or dishes for someone immunocompromised, hand-wash in hot soapy water until the dishwasher is repaired.