Zenith Dishwasher Error Code F18

F18 on a Zenith dishwasher means the turbidity sensor did not detect water in the wash tub during the fill phase. The dishwasher uses this sensor to confirm water is present before starting the wash pump. The cycle stops automatically to protect internal components from running dry. The cause may be a fill system problem, a dirty sensor, or a faulty sensor.

A reset may temporarily clear the F18 code, but if the underlying cause is not corrected, the code will return as soon as the next fill cycle runs. Use a reset only after you have addressed the root cause, such as cleaning the sensor or restoring proper water flow. Repeated resets without repairs will not resolve the issue.

Repair costs depend on the root cause. Cleaning a fouled turbidity sensor costs nothing beyond your time. Replacing a defective water inlet valve or turbidity sensor typically involves parts costs ranging from $20 to $80 depending on the component, plus labor if a technician is hired. A full service call with diagnosis and repair generally runs between $100 and $250.

In many cases, yes. Start by checking that the water supply valve behind or under the dishwasher is fully open and the supply hose is not kinked. Then inspect and clean the turbidity sensor in the sump area, removing any grease or mineral buildup from its lens. If those steps do not resolve the code, further diagnosis of the inlet valve or sensor replacement may require a technician.

No. The F18 code stops the cycle specifically to prevent the wash pump from running without water, which can cause serious mechanical damage. You should not attempt to force the dishwasher through a cycle while this error is present. Address the water supply or sensor issue before running the appliance again.