Dishwasher Not Draining — How to Fix It

Opening your dishwasher to find a pool of standing water at the bottom is unpleasant but common. This issue affects dishwashers of all brands and ages. Before calling a technician (typical service call: CAD $120–$250), there are several checks you can perform yourself that resolve the issue in the majority of cases.

A clogged filter or food trap at the bottom of the dishwasher is the most frequent cause. A kinked or blocked drain hose prevents water from reaching the sink drain or garbage disposal. If connected to a garbage disposal, a blocked disposal or a forgotten knockout plug (on new installations) can cause backup. Air gaps, required by code in some Canadian municipalities, can also become clogged.

A sponge and towels for cleanup, a screwdriver, a small brush or toothbrush for cleaning the filter, and possibly pliers for the drain hose. No replacement parts are typically needed.

1. Remove the bottom rack and locate the filter assembly at the base of the tub. Twist to remove it.
2. Clean the filter under running water, using a brush to remove trapped food debris.
3. Check the drain area beneath the filter for any debris or broken glass.
4. Inspect the drain hose under the sink — ensure it isn't kinked or pinched.
5. If connected to a garbage disposal, run the disposal to clear it. For new installations, check that the knockout plug inside the disposal inlet has been removed.
6. Run a short rinse cycle to test. If water drains properly, the issue is resolved.
7. Going forward, scrape plates before loading and clean the filter monthly.

If the filter is clean, the hose is clear, and the dishwasher still won't drain, the drain pump may have failed. A humming sound during the drain cycle with no water movement is a strong indicator of pump failure. This requires disassembly and a replacement part — best handled by a qualified appliance technician.