FixGrid Academy — Field checklist
Dishwasher Not Draining
Residential dishwasher · Intermediate
Standing water at the end of the cycle. Filter and sump before pump or control.
1Safety first
- Open the breaker or unplug at the junction box.
- Confirm dead with a non-contact tester.
- Stage towels — the sump will spill when you scoop it.
- Gloves and eye protection; mind the chopper and sharp debris.
2First checks
- Confirm the complaint: run a drain and watch for pump sound.
- Scoop the standing water and pull the filter screen.
- Check the drain hose high loop or air gap under the sink.
- Verify the disposer knockout plug was removed on a shared drain.
3Narrow the system
- Split it: external drain path vs sump/filter restriction vs pump or control.
- Check the disposer and sink drain for a shared blockage.
- Listen: pump running with no flow points to a restriction.
- Note any error code the control reports and clear it.
4Highest-probability tests
- Clean the sump, filter, and chopper area; remove glass, seeds, labels.
- Inspect the drain check valve for a stuck flapper.
- Verify power to the drain pump during the drain command.
- Test the drain pump winding and impeller for freedom of movement.
5Common outcomes and watch-outs
- Most common: clogged filter and sump with a restricted check valve.
- Restore the high loop or air gap or you will see siphon-back complaints.
- Show the customer the filter — it prevents the same call next month.
- Verify a complete drain on a full cycle before you close out.