Definition
A wash motor is the electric motor that drives a dishwasher’s wash pump. It spins an impeller that pressurizes water and forces it up through the spray arms to clean the dishes. On most modern dishwashers the wash motor and pump are built as a single sealed assembly mounted at the sump, and many newer units use a quiet, variable-speed brushless (BLDC) motor.
What It Does
When the control board calls for a wash cycle, it powers the wash motor. The motor turns an impeller inside the pump housing, drawing filtered water from the sump and driving it under pressure through the lower and upper spray arms. That spinning spray is what actually scrubs food off the dishes. The motor runs in stages throughout the cycle — pre-wash, main wash, and rinse — cycling on and off as the program dictates.
Where It’s Located
At the bottom of the dishwasher tub, under the sump and filter assembly, accessed from underneath after the unit is pulled out. It sits next to the drain pump but is the larger of the two motors. Brand examples: Whirlpool/KitchenAid use the WPW10757217 wash motor & pump assembly; Bosch and Samsung integrate the wash motor into their circulation pump module.
Common Failure Signs
- Dishes come out dirty even though the dishwasher fills with water
- The dishwasher hums or buzzes but you hear no water circulating through the spray arms
- Loud grinding, whining, or rattling during the wash portion of the cycle
- Spray arms barely spin or do not spin at all
- The cycle stops early or throws a wash/circulation error code
- Motor windings read open or shorted with a multimeter
Typical Replacement Cost
$220–$420 including parts and labor. The wash motor & pump assembly itself runs $90–$200 depending on brand. On dishwashers more than 8–10 years old, a frank repair-or-replace recommendation is provided before the part is ordered.
DIY vs Pro
Pro-recommended. Replacing a wash motor means disconnecting power and water, pulling the dishwasher out from under the counter, laying it back to reach the sump, and swapping the sealed motor/pump assembly — a 1 to 2 hour job with electrical and water connections involved. Book dishwasher repair and it can usually be handled same-day with a stocked part.
Need this part replaced? Call (720) 447-8577 for same-day dishwasher repair in the Denver metro area.
Related Terms
Wash Pump · Circulation Pump · Diverter Motor · Control Board