How to Replace LG Dishwasher Temperature Sensor

The reason this part matters more than its size suggests: the control board cannot manage the heating element without a trustworthy temperature reading. When the thermistor drifts you get a tE code — the board seeing a reading outside any sensible range — or a false HE code, where the board declares a heater fault because the sensor keeps insisting the water is cold while the element is working perfectly.

Prove it is the sensor first#

That second row settles arguments. NTC means negative temperature coefficient: resistance drops as things heat up, so a sensor that does not react to your hand is not reading anything.

If you get an HE code, meter the heating element too. A heater that passes at 10-30 ohms alongside a persistent HE points straight back at the thermistor. Smart Diagnosis in the LG ThinQ app will also report the temperature the board thinks it is seeing, which is a fast way to spot garbage data.

Finding it#

Kill power at the circuit breaker. The sensor lives inside the tub, low down by the sump. Take out the lower rack, lift the pull-up filter assembly straight out, and look into the recessed well at the centre of the tub floor. You are looking for a small plastic-bodied probe with a two-wire connector, protruding from the sump sidewall or clipped to the tub bottom.

On some models the connector sits just above the sump and you can reach it from inside. On others you go underneath: four Phillips screws along the bottom front release the lower access panel, and the connector is in the harness below.

The probe carries only a low-voltage signal, but the heating element beside it runs at 120V — which is why the breaker goes off, not just the machine.

The swap#

Press the locking tab and part the two-pin connector. The sensor is held by one of three things: a small Phillips screw, a plastic retaining clip, or a friction-fit rubber grommet. Screw types come out with the screw; clip types release with a press on the tab; grommet types pull straight out and leave the grommet behind.

Push the new probe into the same housing or grommet. The tip has to sit where water actually collects in the sump — a sensor mounted clear of the water reads air temperature and behaves exactly like a failed one. Snug it down without forcing; overtightening a mounting screw cracks the plastic body.

Reconnect the two-pin connector until the tab clicks. If you worked from below, route the wire along its original path and keep it clear of the spray arm and pump.

Verify before you close it up#

With the connector plugged in, meter the resistance at the harness end. You want that 40K-60K ohms again — that single reading confirms both the sensor and the connection. Then refit the filter, the access panel and the lower rack, restore power, and run a Normal cycle. No tE or HE should appear. Let it run at least 20 minutes and open the door: the water should be hot. Smart Diagnosis should now report a sane temperature.

When the code comes back#

• tE returns with a new sensor — the harness between the sensor and the board is damaged. Trace it for pinching, corrosion or chew marks
• HE persists — meter the element again at 10-30 ohms; it may have genuinely failed between diagnosis and repair
• Erratic readings in Smart Diagnosis — the connector is not fully seated or the pins are corroded. Clean and reseat firmly
• Correct at room temperature but failing mid-cycle — the probe is not reaching the water line in the sump

If the sensor and the heater both test good and the codes keep coming, the control board is next, and that is worth a second opinion before you buy one. Book a repair and we will meter it for you.