Did you know the average dishwasher drains over 6,000 litres of water per year? When the system clogs – even slightly – all that water has nowhere to go. That’s when Toronto homeowners start noticing dirty water at the bottom of the tub, slow draining, or dishes coming out still wet and grimy.

If your dishwasher is not draining, don’t panic. There are a few quick checks you can do before calling for a dishwasher repair.

Let us walk you through the most common causes and the simple fixes that often solve the problem.

Why Your Dishwasher Isn’t Draining

Most draining issues come from food debris, grease buildup, or blockages in the hoses and filters. When bits of pasta, rice, seeds, and grease get washed off your dishes, they often settle in the filter or drain line instead of flushing out completely. Over time, that buildup slows the flow of water until the machine simply can’t drain at all.

Toronto homes – especially older houses and many downtown condos – often have plumbing setups that make dishwashers more prone to clogs. In some kitchens, the dishwasher shares a drain line with the sink, so any blockage in the sink plumbing directly affects how well the dishwasher drains. High-use households, smaller filters in modern energy-efficient dishwashers, and low water pressure can all make the problem show up even faster.

All of this means one thing: even a perfectly working dishwasher can stop draining if the system around it gets clogged.

1. Check the Dishwasher Filter (Most Common Fix)

Your filter sits at the bottom of the dishwasher, right under the lower spray arm. When it’s packed with grease, seeds, pasta, or coffee grounds, water can’t pass through.

How to fix it:

1. Remove the bottom rack.
2. Twist and pull out the filter.
3. Rinse it in warm soapy water.
4. Scrub away any stuck-on food.

A dirty filter is the number one reason dishwashers stop draining – especially if you rinse dishes lightly (or not at all).

2. Inspect the Drain Hose

Your drain hose can easily get kinked or clogged with debris.

Signs there’s a hose issue:

• Water sits in the bottom of the dishwasher
• You hear the drain pump working, but little happens
• The hose feels stiff, bent, or blocked

If you’re comfortable, gently pull the machine forward and check the hose behind it. Make sure it’s not pinched and feels clear.

3. Make Sure the Air Gap or High Loop Isn’t Blocked

Toronto homeowners with newer kitchens usually have a “high loop” instead of a physical air gap. Both prevent dirty sink water from flowing back into the dishwasher.

If this gets blocked, the dishwasher cannot drain.

Tip: Run hot water down the sink for 30 seconds before starting a wash cycle – this helps grease move through the drainage line.

4. Clean the Garbage Disposal (If You Have One)

If your dishwasher connects to a garbage disposal, a clogged disposal can stop drainage completely.

Try this:

• Turn on the disposal
• Run cold water
• Let it flush out debris for 20–30 seconds

Sometimes, a brand-new disposal still has the drain plug inside – meaning the dishwasher hose is blocked. Removing this plug solves the issue instantly.

5. Check the Drain Pump for Obstructions

Small items like glass, bones, bread ties, or seeds can get stuck in the pump. If you hear a humming noise but no draining, that’s your clue.

You can access the pump through the bottom panel, but only try this if you’re comfortable – pumps are delicate and can be damaged easily.

Signs You Need a Professional Repair

If you’ve tried the basics and your dishwasher still isn’t draining, the issue may be deeper:

A failing drain pump

The drain pump is responsible for pushing water out of the dishwasher and into the drain line. When it fails, you might hear a low humming sound or no sound at all during the drain cycle. Pumps can burn out from age, clogs, or electrical issues, and they usually need professional replacement.

Electrical issues

Dishwashers rely on sensors, switches, and wiring to trigger the drain cycle. If a wire is loose, burnt, or damaged, the machine may never receive the signal to drain. Electrical problems can also affect the pump directly, causing intermittent or complete failure.

Blocked internal drain passage

Inside your dishwasher is a narrow passageway that channels water toward the drain pump. Food scraps, broken glass, or even detergent buildup can clog this internal path. Since the blockage is inside the appliance, it’s not visible without opening panels — something best done by a technician.

Faulty sensors

Modern dishwashers use sensors to detect water levels, temperatures, and drain cycles. When these sensors fail, the machine might think it has already drained or may refuse to drain at all. These issues are hard to diagnose without testing equipment, which is why a technician is usually needed.

Broken check valve

The check valve prevents dirty sink water from flowing back into the dishwasher. When it jams or breaks, water can’t move out properly or may even return to the tub. This leads to standing water and repeat drainage problems until the valve is repaired or replaced.

FAQ

1. Why is my dishwasher not draining water?

Most of the time, the issue is a clogged filter, drain hose, or disposal connection. These block water from leaving the tub. In more serious cases, the drain pump or internal sensors can fail and require professional repair.

2. Is it safe to run my dishwasher if it’s not draining properly?

No – running it again can cause flooding or burnout of the pump. When water can’t move out, the machine strains to drain, which can damage the motor. It’s best to stop using it until the issue is fixed.

3. How can I tell if the drain pump is broken?

If you hear a humming noise but no draining, the pump may be jammed or failed. You might also smell a slight burning smell if the pump is overheating. A technician can quickly test it and determine whether the pump needs cleaning or replacement.

4. Can a dirty filter cause a dishwasher not to drain?

Absolutely – a dirty filter is the most common cause. When the filter is blocked, water can’t flow into the drain area. Cleaning it regularly prevents 80% of typical draining issues.

5. Should I fix a draining dishwasher myself or call a pro?

Try basic steps first: clean the filter, check the hose, and clear the disposal. If that doesn’t help, calling a technician is the safest and fastest option. Many internal parts are delicate, and DIY attempts can cause more damage.

6. How often should I clean my dishwasher filter?

For Toronto families that use the dishwasher daily, cleaning the filter every 1–2 weeks is ideal. It keeps food debris from building up and prevents future drainage problems. A quick rinse is usually all it needs.