How to Fix Rinse aid not dispensing on Maytag MDB8959SKZ

Rinse aid not dispensing

This step-by-step repair guide walks you through fixing rinse aid not dispensing on your Maytag MDB8959SKZ. With the right tools and parts, most homeowners can complete this repair in 1–2 hours and avoid a costly service call.

Part of our Top 20 Dishwasher Models & Common Repair Issues Guide. Browse all dishwasher repair guides for related models and issues.

“`html

Common Symptoms & Causes

These symptoms on your Maytag MDB8959SKZ typically indicate the rinse aid is not dispensing correctly during the wash cycle.

Dishes and glasses come out with water spots or streaks after a full cycle
The rinse aid indicator light stays on even after refilling the dispenser reservoir
Dishes feel wet or fail to dry properly at the end of the cycle
The rinse aid cap or dispenser door does not open during the rinse cycle

These issues are most commonly caused by a faulty rinse aid dispenser assembly, a worn or cracked dispenser cap, or a failed wax motor that controls the dispenser door opening mechanism.

“`

Safety First

Unplug the dishwasher from the power outlet before starting any repair — never work on a live appliance.
Shut off the water supply valve before disconnecting any water lines or hoses.
Wear work gloves when handling metal brackets, sheet metal edges, or sharp components.
Take photos with your phone before disconnecting any wiring harnesses or connectors.
Work in a well-lit area with enough floor space to lay removed panels flat.

Tools & Parts Needed

Essential Tools

Phillips #2 screwdriver
Torx T20 screwdriver
Needle-nose pliers
Multimeter
Flashlight

Replacement Parts

Step-by-Step Repair Instructions

Step 1

Open the dishwasher and remove the rinse aid cap by turning it counter-clockwise, then check that the rinse aid level reaches the fill line inside the dispenser reservoir. If the dispenser is empty despite recent filling, the rinse aid is either not being dispensed or is leaking out — knowing the starting level rules out user error before you dig deeper. Pro tip: use a flashlight to clearly see the fill line, as rinse aid is nearly clear and easy to misjudge.

Step 2

Remove the cap and closely inspect the rubber O-ring seated around its base for any cracks, flattening, or deformation. A damaged O-ring breaks the seal and allows rinse aid to slowly leak directly into the tub between cycles, causing the reservoir to drain without actually dispensing during the rinse phase. Replace the cap assembly if the O-ring shows any wear — it is inexpensive and sold as a unit.

Step 3

Locate the rinse aid dosage dial inside the dispenser compartment and turn it between settings, feeling for resistance as it clicks through positions. The dial controls how much rinse aid is released per cycle, and if it spins freely with no detectable clicks or resistance, the dial mechanism is stripped and will not hold a setting. A stripped dial means the dispenser cannot regulate output reliably, so the entire dispenser assembly must be replaced.

Step 4

Disconnect power to the dishwasher at the breaker before proceeding — you will be working inside the inner door panel with exposed wiring. Remove the inner door panel (4 T20 Torx screws) to access the rinse aid wax motor located behind the dispenser housing, then disconnect its harness and test resistance across its terminals with a multimeter set to Rx1; a healthy motor reads 300–500Ω. A reading of infinite resistance (open circuit) means the wax motor has failed and will not open the dispenser door during the rinse cycle — replace the motor.

Step 5

With the dispenser compartment open and dry, locate the small vent opening inside the compartment — this opening allows air displacement so rinse aid can flow out freely during dispensing. If it is clogged with dried or crystallized rinse aid residue, a vacuum lock forms and prevents the rinse aid from releasing even when the wax motor is functioning correctly. Gently clear the opening with a toothpick, being careful not to enlarge or damage the vent hole.

Step 6

Reassemble the door, restore power, and run three consecutive normal wash cycles with the dosage dial set to the mid-range position. After each cycle, open the dispenser and check the fill level — at a mid setting you should see the level drop approximately one-eighth of the reservoir capacity per cycle. If the level does not change across all three cycles despite the previous steps checking out, the dispenser assembly has an internal mechanical failure and should be replaced as a unit.

Where to Buy Replacement Parts

Find genuine OEM and aftermarket replacement parts for your Maytag MDB8959SKZ on Amazon:

When to Call a Professional

If the issue persists after completing all steps above, the problem may involve the sealed refrigerant system, a failed main control board, or wiring that requires specialized diagnostic equipment. Contact a licensed appliance technician — attempting sealed-system repairs without EPA 608 certification is illegal and unsafe.

How Much Does This Repair Cost?

DIY parts for fixing a rinse aid dispensing issue on the Maytag MDB8959SKZ typically cost between $10 and $50, depending on whether you need a new dispenser cap, actuator, or full dispenser assembly. A professional service call usually runs $150–$300 once you factor in labor and parts. Tackling this repair yourself can save you $100 or more.

Frequently Asked Questions

How do I know if the rinse aid dispenser on my Maytag MDB8959SKZ is clogged?

Check the dispenser opening for dried residue or buildup that may be blocking the release. Clean it with warm water and a soft cloth to restore proper flow.

How often should I refill the rinse aid on my Maytag MDB8959SKZ?

Most households need to refill the rinse aid reservoir approximately once a month. Your dishwasher’s indicator light will alert you when the level is low.

Can a faulty dispenser cap cause rinse aid not to dispense?

Yes, a cracked or improperly sealed cap can prevent the dispenser from releasing rinse aid correctly. Inspect the cap for damage and replace it if necessary.

Post Views: 0