Quickly Fix the Drainage Problems on an LG Dishwasher

Defects with dishwasher drainage occur quite often. And as our experience of dealing with LG dishwasher drainage problems shows, the malfunction might often be eliminated with your own hands.

LG dishwasher drainage problems

Drain pump and dishwasher motor

Most models of dishwashers are equipped with a single pump with one electric motor. In fact, the pump has two separate compartments:

  • For circulation of water.
  • For draining water.

Each compartment has its own shaft with impeller.

One of the main parts of a household dishwasher – a drain pump – often becomes the source of the problem associated with poor drainage.

When it comes to LG models of dishwashers using a separate drain pump, it is recommended to inspect inlet/outlet communications of the pump. You need to also make sure that the pump gets power during the drain cycle.

Dishwashers that use a drain valve or solenoid should also be checked for obstructions. It is recommended to measure the resistance of the electromagnetic solenoid coil (valve):

  1. Working condition: the resistance equals several dozens of Ohms.
  2. Non-working condition: the resistance is significantly higher or the value is close to zero.

Integrity of the impeller and motor

Models with a two-section pump might suffer from impeller malfunction. However, it is recommended to check the motor first.

During the standard inspection, you need to check whether the shaft rotates in the right direction. If the motor rotates in the opposite direction or does not rotate at all, check the power at its input terminals according to the circuit designations. With no voltage at all, you need to check:

  • door switches,
  • timer module
  • electronic control module.

If the voltage is okay, but there is no rotation, the motor windings may be damaged. If the motor produces “whistling” sounds, this indicates high load (shaft blockage, short circuit of the stator windings).

Check valve malfunction

Check valve malfunction

Check valve helps to keep water flowing in one direction only.

Check valve prevents dirty water from returning into the dishwasher sump. Typically, it is a simple rubber damper that acts as a part of the drain pump outlet.

If not all water comes out through the drain hose and you suspect that the drains back up into the dishwasher sump, a possible cause may be associated with a failure of the check valve.

The valve should fully open in the drain cycle, but always get back to the closed position in the rinse or circulation mode. In the absence of foreign objects affecting the valve, a clear cause is the “fatigue” of the check valve. Replacement will be the only efficient option here.