On this page
Quick answer
If your dishwasher isn't draining properly, check the air gap. Ensure it's clear of debris and properly installed. If needed, replace the air gap or related parts.
Confirm the symptom
- Dishwasher not draining properly.
- Water backing up into the sink.
- Unpleasant odors coming from the dishwasher.
- Slow draining or standing water in the dishwasher.
- Air gap is clogged or disconnected.
Tools and prep
- Screwdriver (flathead or Phillips, depending on your model)
- Plumber's snake or small brush
- Bucket or towel to catch water
- Replacement air gap (if needed)
- Turn off power to the dishwasher at the circuit breaker.
- Shut off the water supply to the dishwasher.
Step-by-step troubleshooting
- Access the Air GapDo: Locate the air gap on your sink, usually near the faucet. Remove the cap by turning it counterclockwise.Observe: Check for any debris or blockages inside the air gap.Means: If blocked, use a plumber's snake or small brush to clear it.Next: Check the drain hose connection.
- Check the Drain Hose ConnectionDo: Follow the drain hose from the dishwasher to the air gap. Ensure it is securely connected.Observe: Look for any kinks or blockages in the hose.Means: Straighten any kinks and clear any blockages.Next: Test the dishwasher.
- Test the DishwasherDo: Run a short cycle to see if the issue is resolved.Observe: Monitor the dishwasher for proper draining.Means: If the problem persists, proceed to the next step.Next: Inspect the drain pump.
- Inspect the Drain PumpDo: Locate the drain pump, usually at the bottom of the dishwasher. Remove the lower access panel.Observe: Check for any blockages or damage to the pump.Means: Clear any blockages or replace the pump if damaged.Next: Reassemble and test again.
- Reassemble and Test AgainDo: Replace the lower access panel and reconnect any hoses.Observe: Run another short cycle to ensure the issue is resolved.Means: If the problem is still not fixed, consider replacing the air gap.Next: Replace the air gap if necessary.
- Replace the Air GapDo: Purchase a new air gap compatible with your dishwasher model.Observe: Follow the manufacturer's instructions to install the new air gap.Means: Ensure all connections are secure and test the dishwasher again.Next: Call a professional if needed.
Common causes
| Cause | Likelihood | Difficulty | Part often needed |
|---|---|---|---|
| Clogged Air Gap Food particles or debris can block the air gap, preventing proper drainage. | Common | Easy | None |
| Kinked or Damaged Drain Hose A kinked or damaged hose can restrict water flow and cause drainage issues. | Sometimes | Easy–Medium | Drain Hose |
| Faulty Drain Pump The drain pump may be clogged or malfunctioning, preventing proper drainage. | Sometimes | Medium | Drain Pump |
| Incorrect Air Gap Installation If the air gap is not installed correctly, it can cause drainage problems. | Sometimes | Easy | Air Gap |
| Blocked Dishwasher Drain Debris in the dishwasher's internal drain can prevent water from flowing out. | Sometimes | Medium | None |
| Faulty Check Valve The check valve prevents water from flowing back into the dishwasher. If it fails, water can back up. | Rare | Hard | Check Valve |
Parts matching
Ensure you have the correct parts for your dishwasher model. Check the manufacturer's website or consult the user manual for compatibility.
- Air Gap
- Drain Hose
- Drain Pump
- Check Valve
- Plumber's Snake or Small Brush
- Replacement Screws or Fasteners
Always double-check the part numbers to ensure compatibility with your dishwasher model.
When to call a professional
- If the dishwasher still doesn't drain after troubleshooting.
- If you encounter significant water leaks.
- If you're uncomfortable performing any of the steps.
- If the dishwasher makes unusual noises during operation.
- If you suspect a major component failure, such as the motor or control board.
FAQ
Why does my dishwasher have an air gap?
The air gap prevents dirty water from flowing back into the dishwasher, ensuring proper sanitation.
Can I clean the air gap myself?
Yes, cleaning the air gap is a simple process. Remove the cap, clear any debris, and reassemble.
How often should I check the air gap?
It's a good idea to check the air gap every few months to ensure it's clear of debris and functioning properly.
What if the air gap is leaking?
If the air gap is leaking, it may need to be replaced. Ensure all connections are secure and consider replacing it if the issue persists.