My LG dishwasher had an odd problem. Some days it would wash everything in the top basket but not items in the bottom basket, other days it would wash stuff in the bottom basket but not the top.
The dishwasher is still under warranty but LG customer service are more interested in annoying their customers than helping them. They refused to honour the warranty so I guess it’s up to me to fix it myself.
After checking for obvious things like blocked nozzles on the spray arms or clogged filters, I tried an experiment. I pointed the top and bottom spray-arms straight ahead then ran the dishwasher. The bottom arm was still in exactly the same position after the wash. So no water was getting to the bottom sprayer which suggests a problem with the diverter valve which distributes water between the top and bottom sprayers. The cause could have been lots of things including:
- Blocked jets or pipes
- Wiring problem
- Faulty sensor
- Controller board or software problem
- Mechanical jam of the valve
Next I put an AC voltmeter across the valve motor. This proved that power was going to it at the right times, it just wasn’t turning. So it must be either a mechanical jam or a faulty motor. I disassembled the valve itself and it didn’t seem jammed so I guess it’s the motor.
A replacement motor costs $54 from LG but Statewide Appliances in Adelaide have exactly the same part for $18. You have to be a bit of a contortionist to reach under the dishwasher and get to the motor but after a bit of swearing, scrapes and bruises I got it out and swapped in the new one.
Three days and about 7 loads of dishes later and it’s running fine. I call that fixed.