How to Replace a Maytag Dishwasher Drain Valve

The check valve is the one-way gate that keeps drained water from siphoning back into the tub. On current Maytags it is built into the drain pump; on some older models it sits in a separate housing at the pump outlet.

Tools and parts#

• Tools: 1/4-inch hex driver, pliers for the spring clamps, Torx T20 driver, towels, a shallow pan
• Part: check valve flapper, or the complete drain pump WPW10348269 with the check valve built in
• Time: 20-35 minutes
• Difficulty: Beginner to Intermediate
• Safety warning: Disconnect power at the circuit breaker and turn off the water supply. Residual water will be present when you access the drain system components.

Step 1 — Confirm it is the check valve#

The test is simple: run a full cycle, open the door, and confirm the tub is empty except for the normal film in the sump. Close it, wait 2-4 hours, and open again — if water has risen in the tub, something is flowing backward. That is either a failed check valve or a drain hose with no high loop, so check the hose routing before you replace anything.

Step 2 — Drop the lower panel#

With the breaker off and the water shut, remove the kick plate's two 1/4-inch hex screws and set towels and a pan under the drain pump on the left of the tub bottom.

Step 3 — Locate the check valve#

On most current models the valve lives inside the drain pump body, where the flapper lets water out and blocks it from flowing back when the pump stops. On older models a separate check-valve housing sits between the pump outlet and the drain hose. Trace where the drain hose meets the pump to tell which you have.

Step 4 — Get to the flapper#

For an integrated valve, unplug the pump harness, squeeze the spring clamp and pull the drain hose off the outlet, twist the pump counterclockwise off the sump, and look into the port for the rubber flapper. For a separate housing, squeeze the clamps on both ends, pull the hoses, and twist or snap the housing apart to reach the disc inside.

Step 5 — Inspect and replace the flapper#

A good flapper is pliable, clean, and seats flat against its rim. Look for a warped disc that will not seat, debris wedged under it, or a flapper gone cracked and rigid with age. Replace a damaged flapper — but if the seat itself is grooved or corroded, fit the complete pump, since a new flapper cannot seal against a bad seat.

Step 6 — Reassemble and check flow direction#

Install the new flapper or pump so the valve passes water away from the tub and blocks it coming back — mount it backward and the dishwasher cannot drain at all. Reconnect the hose with its spring clamp, plug the harness back in, and twist the pump clockwise until it locks on bayonet-mount models.

Step 7 — Test#

Refit the panel, restore water and power, and run a full Normal cycle. When it finishes and the pump stops, confirm the tub is empty, then close the door, wait 1-2 hours, and check that no water has crept back.

Step 8 — Fix the drain hose loop too#

Even a good check valve backflows through siphoning without a proper high loop. Confirm the drain hose rises and clips to the underside of the countertop, with its highest point above the sink's flood rim, which breaks the siphon regardless of the valve. Treat this as insurance alongside the new valve.

When to call a professional#

Bring in a technician if backflow continues after a new valve and a correct high loop (a deeper under-sink plumbing issue), if the pump housing is cracked and leaking, or if a sewer smell persists after the fix, which can mean a separate drain-venting problem. EasyBear technicians serving Sacramento and the Bay Area carry Maytag parts and diagnostic tools on every call.

• Dishwasher repair service
• Maytag appliance repair
• Dishwasher repair cost guide

Backflow won't stop? Book a same-day Maytag dishwasher repair.