Most Commonly Failing Dishwasher Parts

10 Most Commonly Failing Dishwasher Parts (2025 BC Homeowner’s Guide)

When your dishwasher starts acting up, it’s easy to panic especially if you rely on it daily. Dishes coming out dirty, puddles on the floor, or a machine that just won’t start can feel like a major disruption. However, here’s the good news: most dishwasher issues can be attributed to just a few faulty parts. And the better news? Many of these problems are preventable or at least manageable if you know what to look for  including upgrading drain systems when necessary.

In British Columbia, where water hardness varies significantly by region and energy efficiency has become a household priority, dishwasher wear and tear appear to be different from those in other parts of Canada. Combine that with the fact that many families are trying to extend the lifespan of their older appliances, and it’s no surprise that dishwashers are running into trouble more often.

This guide is here to help. We’ll walk you through the ten most commonly failing dishwasher parts, what each one does, how to spot signs of failure, and how to maintain or replace them effectively. Whether you’re a DIY-savvy homeowner or someone who just wants to understand the repair tech’s language, this is your all-in-one reference.

What Causes Dishwasher Parts to Fail Most Often?

Dishwasher parts don’t fail randomly. In most cases, they follow predictable patterns caused by how the appliance is used, the environment in which it’s located, and the quality of its components. Understanding the root causes of these failures can help you anticipate and prevent problems, keeping your appliance running smoothly for years.

Daily Wear and Tear

Dishwashers operate under extreme conditions hot water, heavy pressure, strong detergent, and constant exposure to food particles. Over time, seals dry out, motors wear down, and spray arms get clogged. It’s normal. But how quickly this happens depends on how often the dishwasher is used and whether it’s regularly maintained.

Water Quality in BC

If you live in areas like the Okanagan, Surrey, or parts of Vancouver Island, hard water could be an unseen enemy. Mineral deposits, particularly calcium and lime, accumulate within components such as heating elements and spray arms. This reduces performance and shortens the lifespan of several key parts.

User Habits and Maintenance

Let’s face it many of us treat our dishwashers like magic boxes that take care of the mess for us. However, overloading racks, skipping routine cleanings, and using the wrong detergent all contribute to faster part failure. Even something as simple as not scraping off food can cause drain and pump issues over time.

Inherent Design Flaws

Newer dishwashers are often designed with cost-efficiency in mind. This means thinner plastics, lower-grade pumps, and more electronics which can all fail faster than the parts found in older, more robust machines. If you’re running a budget model or one that’s already 8–10 years old, you’re more likely to see certain parts go before others.

By understanding what goes wrong and why, you’re better equipped to keep your dishwasher running smoothly and avoid last-minute emergencies.

Top 10 Dishwasher Parts That Commonly Break

Let’s break down the most failure-prone components, how they work, what usually goes wrong, and what to do next.

1. Spray Arms

Function: These spinning arms spray water across your dishes, using high pressure to dislodge food and grease from every angle.

Symptoms of Failure:

• Dishes still dirty or greasy after a cycle
• Odd patterns of clean vs. dirty dishes (e.g., top rack fine, bottom rack dirty)
• Rattling, clicking, or grinding sounds during washing

Quick Diagnostic Tip: Remove the spray arm and hold it up to the light. You’ll likely see small food bits or mineral buildup blocking the holes. If it doesn’t spin freely or looks cracked, you’ve found your culprit.

Maintenance/Fix Advice: Clean with a toothbrush, toothpick, or white vinegar soak. If the arm doesn’t spin freely after cleaning, or if it’s cracked, replace it. Always check both upper and lower arms.

Replace vs. Repair: Cleaning usually restores performance. Replacements are inexpensive and DIY-friendly especially helpful in areas with hard water.

2. Heating Element

Function: This metal loop heats water during washing and aids drying by raising internal temperatures.

Symptoms of Failure:

• Cloudy glassware
• Wet dishes even after the dry cycle
• Unusually long cycle times (due to multiple heating attempts)

Quick Diagnostic Tip: Look for discoloration, bubbling, or visible corrosion on the element under the bottom rack.

Maintenance/Fix Advice: Use high-efficiency or eco-friendly dishwasher cleaners on a monthly basis. Run an empty cycle with vinegar to dissolve mineral buildup. Avoid running the dishwasher on cold cycles consistently, as the element can become less responsive over time.

Replace vs. Repair: Replacement is usually worth it, especially if drying performance is poor. If your machine is over 10 years old, it might also be time to evaluate its overall efficiency.

3. Circulation Pump & Motor Assembly

Function: Circulates hot water through the spray arms to power the wash cycle.

Symptoms of Failure:

• Humming, buzzing, or grinding during cycles
• Poor cleaning results, especially on baked-on food
• The dishwasher seems to run but does nothing

Quick Diagnostic Tip: Listen during the main wash phase. If you hear humming but no water movement, your pump may be blocked, or the motor is failing.

Maintenance/Fix Advice: Clean filters regularly and avoid running cycles with large food debris still on dishes. Some pumps have removable covers for basic cleaning; refer to your user manual for instructions.

Replace vs. Repair: Motors are pricey and tricky to access. If it’s just a blockage, it’s worth fixing. If the motor is gone, evaluate repair versus replacement based on its age.

4. Water Inlet Valve

Function: Regulates the amount of water entering the dishwasher during the fill stage.

Symptoms of Failure:

• The dishwasher doesn’t fill with water
• Starts the cycle but stops within a few minutes
• Humming sound but no visible water flow

Quick Diagnostic Tip: Listen for the “fill” sound early in the cycle. If you hear nothing or just a faint hum, the valve might be stuck or clogged.

Maintenance/Fix Advice: Turn off the water and power, disconnect the hose, and clean the mesh filter. Reconnect and test. If it’s still not working, the valve may need to be replaced.

Replace vs. Repair: Easy to replace on most models and relatively affordable. It’s not worth attempting repair if it’s leaking or electrically dead.

5. Drain Pump & Hose

Function: Sucks dirty water out of the tub and pushes it through the hose into your sink’s drain or garbage disposal.

Symptoms of Failure:

• Water left sitting at the bottom
• Drain cycle sounds longer than normal
• Slow or incomplete draining

Quick Diagnostic Tip: Remove the bottom access panel and inspect the drain hose. If it’s kinked, that might be your issue. Otherwise, remove and flush it out.

Maintenance/Fix Advice: Clean filters weekly and check for clogs. Never flush greasy food bits or starch-heavy leftovers (like rice and pasta) into the dishwasher.

Replace vs. Repair: Hoses can be cleaned or replaced affordably. Pumps are more complex consider replacement only if your unit is relatively new.

6. Door Seal (Gasket)

Function: Prevents water from leaking out the front of the dishwasher.

Symptoms of Failure:

• Drips during or after a cycle
• Moisture on the floor in front of the unit
• Moldy or musty smell when you open the door

Quick Diagnostic Tip: Run your finger along the gasket to check for any irregularities. If it feels cracked, loose, or rough, it may not be sealing properly.

Maintenance/Fix Advice: After each cycle, wipe the gasket down with warm water and mild soap. Slightly ajar, the door should be cracked open to prevent mould buildup and mildew.

Replace vs. Repair: Seals are inexpensive and easy to replace. If it’s old and misshapen, replacing it is a no-brainer.

7. Detergent Dispenser

Function: Releases detergent and rinse aid at the correct point in the wash cycle.

Symptoms of Failure:

• Soap pod or powder still sitting inside after wash
• Dishes come out greasy or with food residue
• The compartment door is stuck closed

Quick Diagnostic Tip: Manually open the compartment and test the spring for proper operation. If it’s sticky or jammed, it may simply need a thorough cleaning.

Maintenance/Fix Advice: Rinse the dispenser after every few loads, and don’t overfill it. Clean out any hardened detergent using a soft brush and warm water.

Replace vs. Repair: Replace if the spring mechanism or solenoid fails it’s usually a one-piece assembly.

8. Float Switch

Function: Controls the amount of water entering the tub by detecting the water level.

Symptoms of Failure:

• The dishwasher won’t fill
• Overfilling and leaking
• The cycle starts but shuts off quickly

Quick Diagnostic Tip: Gently tap the float (usually located in the front corner of the tub). It should move freely up and down. If it sticks, it’s likely the issue.

Maintenance/Fix Advice: Clean under and around the float to clear out grease, food, and calcium buildup.

Replace vs. Repair: If cleaning doesn’t solve the issue, the switch itself is inexpensive and relatively easy to replace.

9. Door Latch Assembly

Function: Locks the dishwasher door and signals the control panel it’s safe to start the cycle.

Symptoms of Failure:

• Machine won’t start
• The cycle starts, but then stops suddenly
• The door won’t close or pop open mid-cycle

Quick Diagnostic Tip: Close the door gently and listen for a firm “click.” No click = likely latch failure.

Maintenance/Fix Advice: Clean the latch mechanism and make sure nothing is obstructing the door. Misalignment can sometimes be fixed by adjusting screws.

Replace vs. Repair: If the latch breaks or wears out, it must be replaced; there is no workaround here.

10. Electronic Control Board

Function: This is the brain of the dishwasher, responsible for managing each part of the cycle and coordinating inputs from other components.

Symptoms of Failure:

• Dead control panel
• Random button presses or cycle resets
• Intermittent issues or power glitches

Quick Diagnostic Tip: Unplug the dishwasher or flip the breaker for 10 minutes. This hard reset sometimes resolves temporary glitches.

Maintenance/Fix Advice: Avoid electrical overloads by using surge protection. Keep the area around the board dry and clean.

Replace vs. Repair: If the board is fried or unresponsive, replacement is your only option, and it’s usually not a DIY job.

How to Prevent Dishwasher Part Failures

Preventing part failures doesn’t require a technician; just a few regular habits can go a long way:

• Run hot water before starting: This ensures your first fill is already warm, which improves cleaning and reduces strain on the heater.
• Clean filters regularly: A clogged filter forces pumps and motors to work harder, reducing their lifespan.
• Use high-quality detergent and rinse aid: Cheap detergent can leave residue and accelerate buildup.
• Deep clean monthly: Run an empty cycle with white vinegar or a dishwasher cleaning tab.
• Don’t overload racks: Blocking spray arms and restricting water flow reduces efficiency and increases wear.

Repair vs. Replace – When to Call a Pro

Dishwashers generally last between 8 and 12 years. If yours is approaching that upper range and you’re experiencing multiple part failures, it might be more economical to replace the unit entirely.

Here’s how to decide:

• Over 10 years old? Start weighing total costs.
• Multiple components failing in a short time? This could be a sign of more significant internal wear.
• Repairs exceed 50% of replacement cost? Go for the new unit.

And if you’re in BC, check if your household qualifies for local rebates on ENERGY STAR® dishwashers, especially if your old one is inefficient or energy-hungry.

Conclusion

Dishwashers are hardworking machines, but they’re not immune to problems, especially as they age. Knowing which parts fail most often and how to maintain or replace them can help you avoid costly surprises and keep your kitchen running smoothly.

Whether you’re cleaning out a clogged spray arm or calling in a technician to replace a faulty pump, staying informed is your best defence against downtime and dishwashing disasters.

And if your dishwasher has been giving you trouble, let us help. From quick diagnostics to professional repairs across BC, we’ve got the expertise to keep your kitchen humming.