Fixed No Drain Now Fill Valve Fault Shows Two Fault Decision Tree

Why this matters

When you fix a no-drain washer or dishwasher and a fill-valve fault shows up right after, you are almost always looking at a second, independent failure that the drain problem was hiding. A unit that would not drain stayed full of water, so the control never reached the next fill cycle and never exercised the inlet valve under normal conditions. Restore the drain and now the machine fills, drains, and refills repeatedly, and a weeping or slow-closing inlet valve, a failing pressure switch, or a clogged inlet screen finally surfaces as an overfill, a slow fill, or a no-fill fault. This is a genuine two-fault scenario, not a comeback on your drain repair. This tree confirms the drain fix held and isolates the fill-side component that was masked by the standing water, so the unit does not bounce back overfilling or refusing to fill.

Symptom presentation

Drainage was restored and the unit drained normally, then a fill problem appeared: the washer or dishwasher overfills past its level, fills too slowly to reach level in time, or will not fill at all and throws a fill or long-fill fault. The owner reports it drains fine now but flooded, would not fill, or sat half-full, which is the fill-side signature. On a washer with a pressure switch, the control may report level errors; on a dishwasher with a float and flow meter, it may report a fill timeout or overfill. The drain pump now runs correctly, ruling out the original complaint.

Quick checks

With the drain repair confirmed (pump runs, hose and check valve clear, drains to empty), focus on the fill path. Check the inlet valve screens for sediment; a clogged screen slows fill and is the first thing to inspect after any drain or plumbing disturbance that stirred up the supply line. Energize the inlet valve and confirm it opens fully and, critically, closes completely when de-energized; a valve weeping when off causes a slow overfill that the level sensor eventually catches. Read the valve solenoid coils for correct resistance against the tech sheet (commonly several hundred ohms per coil; a dual-coil hot/cold valve reads each independently). On a washer, check the pressure switch and its air dome (pressure) hose for a kink, leak, or clog that makes the control misread level; blow through the hose to confirm it is clear and seats on both ends. On a dishwasher, check the float for free movement and the flow meter or fill timing for correct volume, since the control fills by counting meter pulses or by timed fill plus float backup. Confirm water supply pressure is adequate, since a partly closed supply valve mimics a slow fill and produces a long-fill timeout. Verify the inlet hoses and any anti-flood (auto-shutoff) device are not tripped or restricted.

Isolation tree

Branch 1, inlet valve closing. A valve that does not seat fully when de-energized lets water trickle in and slowly overfills the tub even after the cycle ends. De-energize the valve and watch for any flow; weeping confirms a failed valve. Replace the inlet valve and confirm fill stops cleanly on command.

Branch 2, inlet screens and supply. Sediment-clogged inlet screens or a partly closed supply valve produce a slow fill and a long-fill timeout. Clean the screens, open the supply fully, and confirm fill reaches level within the rated time. Restored fill speed confirms a restriction, not a control fault.

Branch 3, pressure switch / level sensing (washer). A pressure switch with a leaking or clogged air dome hose misreads level and triggers overfill or underfill faults. Inspect the air dome hose for kinks, leaks, and obstruction, and read the switch transitions against the tech sheet. Replace a faulty switch or repair the hose, then confirm the control reads level correctly.

Branch 4, float and flow meter (dishwasher). A stuck float or a miscounting flow meter causes overfill or fill-timeout faults. Confirm the float moves freely through its travel and the float switch transitions, and verify the flow meter counts a correct fill volume by watching its pulse count or the metered fill quantity against the tech sheet. Replace the stuck float switch or a flow meter whose impeller is bound by debris, then confirm metered fill reaches level on count.

Branch 5, control reading the level circuit. If the inlet valve, screens, level sensor, and supply all check good but the fault persists, the control may be misreading the level input or mistiming the fill. Verify the harness from the pressure switch or flow meter to the board is intact and the connector is seated, since a drain repair often involves moving the unit and disturbing harnesses. A fault that clears after reseating a connector points to a disturbed connection rather than a failed sensor or board.

Confirming diagnosis

Confirm by running several complete fill-and-drain cycles and watching the level reach and hold correctly, then stop cleanly. The inlet valve must close fully with no weep, fill must reach level within the rated time, and the level-sensing device (pressure switch or float/flow meter) must report accurately. No overfill, slow-fill, or no-fill fault should recur across multiple cycles. Only repeated clean cycles confirm both faults are resolved, the original no-drain repair and the revealed fill-side failure.

Remediation

Replace a weeping or non-closing inlet valve, clean clogged inlet screens, open a throttled supply, repair or replace a faulty pressure switch and its air dome hose, or replace a stuck float switch or miscounting flow meter, depending on which fill component the drain repair exposed. Run multiple complete cycles to verify fill and level. Document this as a second, independent fill-side fault uncovered by the drain repair, not a return of the no-drain problem, so the customer understands the sequence.

References

• UL 2157, Standard for Electric Clothes Washing Machines, water-fill and overflow requirements.
• UL 749, Standard for Household Dishwashers, fill-control and overfill-protection requirements.
• AHAM HLW-1 and DW-1, washer and dishwasher performance bases.
• OEM Washer/Dishwasher Tech Sheet, inlet-valve coil resistance, pressure-switch transitions, and float/flow-meter specifications.