Dishwasher Not Draining? Here Is What to Check First

You open the dishwasher expecting clean dishes and find a pool of murky water sitting in the bottom. It is one of the most common appliance complaints we hear at Al's Appliance, and the good news is that the cause is often simple. Before you assume the worst, work through this checklist.

1. Check the Filter

Most modern dishwashers have a removable filter at the bottom of the tub. Food scraps, glass fragments, and grease build up there over time and block drainage. Twist it out, rinse it under hot water with a soft brush, and pop it back in. If you have never cleaned yours, this is the most likely culprit.

2. Look at the Drain Hose

The hose that runs from your dishwasher to the sink drain can kink, especially if the unit was recently moved or something heavy was pushed against it under the sink. A kinked or clogged hose stops water cold. Straighten any bends and check where it connects.

3. Clear the Air Gap or High Loop

If you have a small chrome cylinder beside your faucet, that is an air gap, and it can clog with debris. Pop the cap and clear it out. No air gap? Make sure the drain hose loops up high under the sink before connecting to the drain.

4. Run the Garburator

If your dishwasher drains into a garburator, a full or clogged disposal blocks the shared drain line. Run it for fifteen seconds with water flowing. Also, if the disposal was recently installed, check that the knockout plug was removed. This is a surprisingly common cause.

5. Listen for the Drain Pump

Start a drain cycle and listen. A humming noise with no water movement often means something is jammed in the pump, frequently a shard of broken glass. Silence can mean the pump motor has failed. Either way, this is where do-it-yourself usually ends.

6. Consider the Check Valve and Solenoid

Some models use a check valve or drain solenoid that can stick or fail with age. These parts are inexpensive, but diagnosing them correctly takes experience and the right tools.

When to Call a Professional

If you have cleaned the filter, checked the hose, and cleared the air gap and the water still will not move, the problem is likely the pump, valve, or an internal clog you cannot reach. Repeated draining problems can also damage flooring if water finds its way out, so it is not worth ignoring.

Al's Appliance provides fast in-home dishwasher repair across Kitchener, Waterloo, Cambridge, and Guelph. We diagnose on site, quote honestly, and carry parts for all major brands. And if your dishwasher is simply at the end of its life, we have new and used replacements ready to go at prices that make sense.

Stop hand-washing around a broken machine. Call Al's Appliance at 519-824-8828 or visit alsappliance.ca to book your repair.