If your dishwasher finishes its cycle and leaves water sitting in the bottom, work through these seven checks in order. The first three you can do yourself in about fifteen minutes. If none of them fix it, the drain pump or the control board is the likely culprit and that is a service call.
1. The filter
Pull the bottom rack and twist out the cylindrical filter in the sump. On a machine that has never been cleaned, this is usually where the problem ends. Rinse it under hot water and scrub the mesh with an old toothbrush. In Hamilton, scale builds on this mesh faster than the manual assumes.
2. The air gap
That small chrome cylinder on the counter next to the tap is an air gap, and it clogs. Twist the cap off, lift the cover, and clear whatever is inside. If water spurts out of it during a cycle, that is your sign.
3. The garburator plug
This one catches out anyone who has recently had a new dishwasher installed. If the drain hose runs into a garburator, the knockout plug inside the disposal inlet has to be removed. If it was left in, the dishwasher has nowhere to drain to. It is a two minute fix and it is more common than you would think.
4. The drain hose
Look under the sink. The hose should rise into a high loop before it drops to the drain. Without that loop, sink water siphons back into the dishwasher. Check for kinks where the hose passes through the cabinet wall, which happens when someone has pushed the machine back in too hard.
5. The check valve
A small one-way valve stops drained water coming back. When it sticks, you get dirty water in the tub at the start of a cycle rather than the end. It is a cheap part but it sits inside the sump.
6. The drain pump
Listen at the end of the cycle. A working drain pump makes a distinct hum for 30 to 60 seconds. Silence means either a seized impeller, usually from a piece of glass or a fruit sticker, or a dead pump. A grinding noise means something is caught in it.
7. The control board
If the pump has power and still will not run, or the machine skips the drain step entirely, the fault is upstream. This is the point where guessing gets expensive, because control boards are the priciest part in the machine.
What we would do
Checks one to four cost nothing but time. If you get to five, book it. We handle dishwasher repair in Hamilton seven days a week and carry drain pumps and check valves for the brands we see most. If the water is coming from scale rather than a part, read our guide on how hard water damages dishwashers in Hamilton. Call (289) 768-1936 or see the areas we cover.
Common questions
Why is there water in the bottom of my dishwasher?
A shallow pool at the bottom of the sump is normal on most machines. Water covering the filter or sitting above the lower spray arm is not, and it usually means a blocked filter, a clogged drain hose, a jammed drain pump or a failed check valve.
Can I fix a dishwasher that will not drain myself?
Often the first three checks solve it: clean the filter, clear the air gap and check that the garburator plug was knocked out if the dishwasher was newly installed. Anything past that involves the drain pump or the control board and is worth a technician.
Does hard water cause dishwasher drainage problems?
Yes, indirectly. Hamilton water leaves scale on the filter mesh and inside the drain path, which narrows it over time. Machines here tend to need their filters cleaned more often than the manual suggests.
