A dishwasher leak that appears only during some cycles is confusing. The unit might work fine on quick wash, but the floor ends up soaked after heavy or rinse cycles. It feels random, but there’s always a cause. At Edmonton Repair Appliances, we’ve seen these selective leaks many times. Each cycle behaves differently, so a leak in one and not the other usually points to specific settings, water usage patterns, or timing of internal actions. We’ll break down what to look for in each area, how to check safely, and when you might need help from someone with experience in appliance repair services in Edmonton.
Understand How Each Cycle Operates
Each cycle in a dishwasher uses a different amount of water, temperature, and spray pattern. That’s why one cycle might expose a flaw the others don’t.
Heavy and deep clean settings spray more water for longer periods. Therefore, they’re more likely to expose weak seals or cracks. In contrast, a quick cycle runs fast with less water and doesn’t build as much pressure. Leaks only during heated dry suggest something related to expansion or venting.
Our team always starts by testing different cycles with the door panel removed. We do this to observe when and where leaks begin. That way, we avoid guessing and go straight to the actual issue. Understanding the link between cycle behavior and symptoms helps us work smarter and minimize water damage.
Image alt text: Dishwasher control panel with multiple cycle settings displayed
Related tip: If you want to learn more about resolving dishwashing issues, visit our dishwasher repair Edmonton service page.
Inspect the Door Gasket and Spray Pressure
Water leaks near the front during intense cycles often come from the gasket. This soft rubber seal keeps water in place while the spray arms do their job. However, during long cycles, pressure increases and can push past weak or worn seals.
Check the gasket for cracks, flattening, or mold buildup. To clarify, you can test it by placing a thin piece of paper in the door and closing it. If it pulls out easily, the seal is weak in that spot.
Another factor is spray arm pressure. If it’s too strong or misdirected due to a clogged nozzle, water may be pushed toward the corners. This tends to happen more on long cycles, when buildup on the arms reduces control. We often clean the arms and inspect the pump to restore balance.
Monitor When the Leak Starts
Timing tells us a lot. Leaks that happen right at the start usually point to the inlet valve or door seal. Those that appear mid-cycle suggest problems inside the tub or sump area. And if it starts during draining, then it’s more likely tied to the drain hose or pump.
We typically place a dry paper towel under the unit and watch when moisture appears. This simple step reveals whether the leak starts when water fills, sprays, or drains.
One overlooked issue is the water inlet valve not shutting off completely. For instance, if water continues to flow even when the cycle is paused, pressure builds and causes overflow. Fixing that requires replacing the valve, which connects to both the supply line and control board.
If you’re ever unsure which part may be causing it, a good next step is to explore full appliance repair services in Edmonton. Sometimes there’s more than one failure, and checking each section separately prevents confusion.
Check the Float and Overfill Sensor
Older dishwashers use a float switch to monitor water level. If the float gets stuck or the switch fails, the unit overfills. That usually doesn’t show up until heavy or soak cycles run, since those call for more water.
In newer models, a sensor detects water depth electronically. If this sensor becomes dirty or misaligned, it gives false readings. As a result, water keeps filling beyond safe levels.
We clean the float area and gently test its movement. A stuck float won’t rise, so the machine keeps filling. We also check the wiring and sensor housing, especially if the leak is consistent but not severe. It’s a small issue but has a big impact on flooding risk.
Investigate the Lower Spray Arm or Diverter
Some units use a diverter to send water to different arms during a cycle. This part switches flow from the lower arm to the upper or top sprayer. If it sticks or malfunctions, water pressure can get trapped or redirected unexpectedly.
This misdirection causes unusual spray angles. Water may hit the door at the wrong angle or flood sections not designed to handle continuous pressure. This issue mostly shows up during long or sanitize cycles when diverters are used more often.
When we inspect these units, we look for damage near the motor or signs of water hitting the inner panel wrong. One trick is to place a small camera or mirror inside and run a short test to catch movement.
For leaks starting under the unit during these cycles, this area is often the cause.
Check the Filter, Drain Hose, and Air Gap
Grease or food buildup in the filter can cause a blockage. Water pools in the base, and as more enters the tub, it eventually overflows. This doesn’t always trigger an error code.
The same applies to the drain hose. A partial clog or kink means water can’t exit fast enough during heavy drain cycles. So during high water volume phases, the overflow has nowhere to go. That pressure builds and causes leaks through the base or lower panel.
Also, some setups use an air gap—a small fixture on the sink that keeps drain water from backing up into the unit. If that air gap is clogged, water may escape during rinse or drain phases.
When these are missed, people often assume the leak is inside the machine. But restoring drainage clears the problem without replacing internal parts.
Look Below the Unit for Cracks or Seals
Sometimes the tub itself has a small crack that doesn’t show up right away. Heat expansion during longer cycles opens the crack slightly, allowing water to pass. It then closes again when cooled, making it hard to spot unless you know what to look for.
We run long cycles with a mirror or small flashlight placed below. If any moisture appears beneath the center of the unit, the issue is often tub damage or failed bottom seals.
Another common source is the sump gasket. This connects the wash motor to the tub and handles constant pressure. A worn or torn seal here can leak when high-pressure cycles activate.
At this point, it’s usually time to schedule help. If your dishwasher starts leaking during specific cycles and you’ve already ruled out surface issues, our contact page can help you book a technician directly. Edmonton Repair Appliances responds locally and fast.
FAQs
Why does my dishwasher only leak during the rinse cycle?
This cycle uses more water and may trigger overflow if the float or drain system fails. Clogs or overfill sensors often play a role.
Is it safe to run a leaking dishwasher on short cycles?
It may seem fine, but pressure still builds. Avoid using it until you know the cause. Damage can spread fast.
How can I tell if the door seal is the problem?
Try the paper test: place paper at the seal, shut the door, and pull. If it slides out easily, the seal is weak.
Do newer dishwashers still use float switches?
Many now use electronic sensors. These are more accurate but can still fail or misread water levels due to buildup or positioning.
Can cycle-specific leaks damage my floor long term?
Yes. Even small leaks cause mold and wood damage under flooring. Fixing it early prevents major repairs later.