LG Dishwasher Will Not Start — Causes & Fix

Quick Answer: Why Your LG Dishwasher Will Not Start#

Most likely: the answer sorts into three categories by symptom. A completely dead LG dishwasher — no lights at all — has lost power, whether a tripped breaker or GFCI, a loose hardwire connection, or a blown onboard control-board fuse. A lit panel that ignores the Start button is usually the door latch not confirming closed, or an accidental Child Lock or Delay Start. And a unit that clicks then immediately stops points at an intermittent door switch or the Inverter Direct Drive motor detecting a locked impeller and protecting itself. Decide which of the three you have before you open anything.

Likely Causes at a Glance#

Walking Through the Diagnosis#

Start with power. If nothing lights at all, test the outlet with a lamp or charger, check the breaker and any GFCI, and on a hardwired unit inspect the junction box beneath the dishwasher for loose wires or corrosion; LG boards also carry an onboard fuse that a surge can blow, cutting all power. If the panel does light but Start does nothing, work the safety interlocks and interface: open and firmly re-close the door and listen for a definite latch click, since an unconfirmed latch is the single most common cause in this group. Then rule out the modes — clear a Child Lock by holding the Lock button for three seconds (or Rinse + Dry together for three seconds on models without a Lock key), cancel a Delay Start countdown, and exit demo mode by holding Delay Start + Cycle while powering on for five seconds. A leftover error code from a previous cycle can also block a new start, so power off and on, and if it persists do a five-minute power-disconnect hard reset.

If the panel is lit, everything external checks out, and it still will not run, or if it clicks and stops instantly, move to the machine. A door switch that passes the initial check but opens under motor vibration causes the click-then-stop pattern, as does the Inverter Direct Drive motor shutting down when it senses a locked impeller or an open thermal cutout after an overheat. When all of that passes, the control board's main relay may have failed to energize the motor circuit — inspect the board (remove the door from its hinges and open the panel, eight Torx T15) for burned components or bulging capacitors. LG's ThinQ Smart Diagnosis can still read a non-starting unit if its communication module has power, and a replacement board must match the full model number, such as an LDT7808ST.

Repair or Replace? The Short Version#

Re-seating a latch, clearing a lock, or resetting a code costs nothing, and a door switch or latch assembly is an inexpensive part on an LG worth keeping. Only a control board — model-specific and sometimes needing a firmware transfer — pushes the cost up, and it still stays under a new machine. Because unresolved error codes can escalate into non-start conditions, addressing them early pays off. If diagnosing the board or the Inverter Direct Drive motor is not for you, our technicians run the LG start sequence and confirm the cause first — book a repair.

Frequently Asked Questions#

What should I check first when my LG dishwasher will not start?#

Categorize it. If it is completely dead, check the outlet, breaker, GFCI, and — on hardwired units — the junction box and the onboard board fuse. If the panel lights but Start does nothing, re-close the door for a firm latch click and rule out Child Lock and Delay Start before opening the machine.

How do I turn off Child Lock on an LG dishwasher?#

Hold the Lock button for about three seconds until a tone confirms and the lock icon clears. On models without a dedicated Lock button, hold Rinse + Dry together for three seconds instead. If a countdown is showing, that is Delay Start — clear it with the Cancel/Drain button rather than the lock control.

My LG dishwasher clicks then stops immediately — what is it?#

That pattern usually means the door switch passes its first check but opens under motor vibration, or the Inverter Direct Drive motor senses a locked impeller and shuts down to protect itself. Check the door switch and latch alignment first, then look for debris jamming the impeller before suspecting the board.

Do I need a new control board?#

Only after the power, latch, lock, and error-code checks all pass and the motor is free. Then a failed main relay on the board is the likely cause. LG boards are model-specific — match the full model number like LDT7808ST — and some require a firmware transfer, which is a dealer-level step.