5 Common BOSCH Dishwasher Problems & Easy DIY Fixes

Is your Bosch dishwasher not draining, leaking, or showing error codes? Learn how to troubleshoot and fix the 5 most common Bosch dishwasher problems yourself.

What are the most common problems with Bosch dishwashers?

Bosch dishwashers are high quality machines, but they tend to have five common problems that resurface in every model. These issues involve drainage, cleaning performance and the picky mechanical sensors. Read this list for a quick troubleshoot, and then jump below for more detailed explanation:

1. Dishwasher is not draining, or slow to drain. This is usually caused by a clogged filter, or occasionally a kinked drain hose.
2. An E15 Error Code shows when water has leaked into the base of the unit, triggering a built-in flood sensor. Our other article explains in great detail. Click here.
3. If the Bosch dishwasher is not drying your dishes, you may lack the heat necessary for the drying condensation process. The water must be hot for the dishes to clean properly and also to dry. Another possible cause is a lack of rinse aid, which helps to break up surface tension of the water.
4. If your dishwasher is not filling with water or cleaning well, it might be due to a malfunctioning water inlet valve. The unit must have unrestricted flow of clean water.
5. A blinking red Info Light signifies the door isn’t latched properly, or you may have interrupted the wash cycle.

How to Fix a Bosch Dishwasher That Won’t Drain

If you find standing, dirty water at the bottom of your tub, you likely have a blockage in the filtration or pump system. This is a common cause for E24 and E25 error codes and should be addressed immediately for sanitation. Read about Drain Error code: Troubleshooting Bosch Dishwasher E24 E25 Error Codes. Start by addressing a blockage in the system, and then jump below for info on replacing the check valve.

How to Fix Filtration Blockage:

• Clear the Standing Water: Remove the bottom rack and use a cup to ladle out as much water as possible. A sponge or rags will also come in handy. You’ll have a better view of the components after the water is removed.
• Dry the Sump: Once most of the water is removed, place a dry rag all the way into the washer drain to remove all the water and junk.
• Gain access to the Impeller: Use a screwdriver to loosen the nut on the pump cover. Remove the cover to reveal the drain pump impeller.
• Clear Obstructions: Manually spin the impeller to check anything jamming it like toothpicks or glass. Remove any blockages you find.

• Check Valve: Pull out the rubber check valve (the small plastic/rubber flap) and make sure there is no debris that keeps it from moving. Read below on how to replace if damaged.
• Flush the System: Pour a small amount of clean water through the impeller area to see if it flows freely or if more debris surfaces. It might take a couple of tries to loosen the debris problem.

• Slow Draining Water: Hard water limescale and grease can clog the filter, causing a very slow drain. Use a product like Finish Dual Action Dishwasher Cleaner or Affresh Dishwasher Cleaner Tablets as a monthly preventative measure.

New Install Tip: If the pump is clear but the dishwasher still won’t drain, check the air gap on your sink or the garbage disposal connection. A new disposal often has a knock-out plug that must be removed for the dishwasher to drain.

How to Fix Damaged Check Valve:

If your Bosch dishwasher fills up with dirty water and does not drain at all, it is likely the check valve is damaged. The purpose of the check valve is to allow the water to flow in one direction only, preventing dirty water from flowing back into the dishwasher from the sink. Over time, the valve can get brittle or stuck in the open position by wash debris.

Two locations, depending upon model number. On some models, the check valve will be located by the drain pump inside the dishwasher tub (see photo above).

How to Replace the Internal Check Valve:

• Open the dishwasher door and remove the lower washer rack.
• Lift the lower spray arm up and set it aside.
• Next, remove the filter screen basket and filter screen.
• Reach in and unscrew the cover. Lift the cover up and pull it out of the washer.
• Use a flathead screwdriver to wiggle the damaged check valve out of the dishwasher.
• Place the new check valve where the damaged one was located.
• Once it is in the slot, press it in to ensure that it is firmly in place. Reassemble the dishwasher.

External/Lower Check Valve

In many Bosch 300, 500, and 800 series models, if you don’t see the little rubber flap inside the sump under the filters, it’s likely because your model uses this external check valve underneath the machine. Different type of check valve located underneath the dishwasher (see image below).See below:

How to Replace the External Bosch Check Valve

• Cut Power and Water: Safety first. Unplug the dishwasher or flip the circuit breaker. Turn off the water supply valve (usually located under the sink).
• Remove the Bottom Kickplate: Unscrew the two screws holding the toe kick (base panel) at the very bottom front of the machine. Set the panel and insulation aside.
• Pull the Dishwasher Out: You may need to lower the leveling legs to slide the unit out about 12–18 inches from the cabinetry to get enough clearance.
• Locate the Valve: Look for a small, clear or white plastic component integrated into the drain hose assembly near the drain pump.
• Disconnect the Drain Hose: Use pliers to squeeze and slide back the tension clamps holding the hoses to the valve. Have a towel ready to catch residual water.
• Swap the Valve: Pull the old valve out of the hose housing. Note the direction of the arrow on the part—the new valve must be installed with the arrow pointing away from the dishwasher toward the house drain.
• Secure and Test: Reattach the hoses and clamps. Slide the unit back in, turn on the water and power, and run a “Rinse” cycle to check for leaks before replacing the kickplate.

E15 Error Code

The E15 error code on a Bosch dishwasher indicates that the safety switch has detected water in the lower base tray of the appliance–the trough. This code an anti-flooding feature that prevents water from leaking all over the floor. It’s usually caused by a leak in the sump basin, water tank, or hoses. Worst case, the leak might come from a broken fixture.

Read Here for an Extensive Guide on Repairing and Clearing the E15 Error Code

Bosch Dishwasher Not Drying Dishes

When a Bosch dishwasher leaves your dishes wet, it is usually due to a lack of heat (heating element) or a failure in the moisture-removal process.

Bosch dishwashers do not use an exposed heating element but use an advanced ventilation system. 100 & 300 Series dishwashers use a PureDry technology that incorporates heated water causing condensation on the stainless steel walls. This water drains off easily. The 500 Series uses this same system, but adds an automatic door release to allow steam to escape. CrystalDry is a method used in 800 series & Benchmark models; Zeolite minerals transform moisture into heat (up to 176°F) for optimal drying.

Diagnostic Guide

• Faulty Heating Element/Heat Pump: If the water isn’t getting hot during the cycle, the dishes won’t have enough residual heat to evaporate the moisture. A defective element will often trigger an E09 error code. Use a multimeter to check for continuity; if the circuit is broken, the part is burnt out and requires replacement.The Bosch Dishwasher Heating Element is a direct replacement for models triggering an E09 code, restoring the high-temperature rinse needed for evaporation.
• Inspect the Dishwasher Vent: Many Bosch models use a fan to pull moist air out of the tub. If this fan motor burns out, the steam stays trapped on the dishes. For models with a dedicated vent, ensure the flap opens fully during the drying cycle. If it sticks or remains closed, steam cannot escape; replace the vent assembly with an exact match for your model. If the vent opens but dishes stay wet, the fan motor may have failed. Test the fan motor with a multimeter; if your multimeter shows a dead motor (OL), replace it with the OEM Bosch Vent Fan Motor.
• Malfunctioning High-Limit Thermostat: This safety device shuts off the heat if it thinks the unit is overheating. If it’s “tripped” or faulty, the heater won’t turn on at all.

Safety Tip: When testing for continuity, always ensure the dishwasher is completely unplugged. A continuous reading (usually a beep or a low Ohms number) means the electrical path is intact; “OL” or no reading means the part has failed.

Drying Issues with 800 Series and Benchmark

1. Zeolite Drying System Failure (E07)

On high-end models, the Zeolite container uses minerals to generate heat for drying. If the fan or the heating element within this closed system fails, you get an E07 error.

• The “Hidden” Issue: Unlike standard heating elements, this is a complex mechanical assembly located in the rear right corner.
• The Fix: Often requires replacing the entire Zeolite fan motor or the container itself if moisture has entered the system.

2. CrystalDry Fan Blockage

Similar to Zeolite, the CrystalDry system (found in many 2024–2026 models) uses a dedicated fan to circulate air.

• The Symptom: Extremely poor drying performance without a specific error code.
• The Fix: Users should check if a stray piece of plastic wrap or a thin lid has been sucked into the rear air intake, stalling the fan.

Simple Fixes and Maintenance for Drying Issues

• Empty Rinse Aid: This is the #1 cause of poor drying. Rinse aid breaks the surface tension of water, allowing it to sheet off rather than bead up. Check your “Refill Rinse Aid” light.
• Plastic Items: Plastic doesn’t retain heat as well as ceramic or glass, so it will almost always stay wetter.
• Water Temperature: Ensure your hot water heater is set to at least 120°F (49°C). If the incoming water is too cold, the dishwasher spends its energy heating the water rather than drying the dishes.
• Pro Tip: Try using the “Sanitize” or “Extra Dry” button. This raises the final rinse temperature, making the dishes hotter so they dry faster once the door is opened.

Bosch Dishwasher Fills with Water When Off

If you find clean water pooling in your dishwasher tub while it’s not in use, you likely have a faulty water inlet valve. This issue is often caused by hard water mineral deposits that jam the valve in the open position, allowing water to seep in constantly. Because this can lead to water waste and potential floor damage, it is a high-priority repair that requires a full part replacement.

Step-by-Step Replacement Guide

• Confirm the Source: If the water in the tub is perfectly clear, it is coming from the supply line via a stuck inlet valve. If the water is dirty, the issue is likely a drainage or backflow problem.
• Turn Off Power and Water: Before starting, unplug the dishwasher (or turn off the breaker) and shut off the dedicated water supply valve under the sink.
• Access the Valve: Most Bosch inlet valves are located at the bottom-rear of the unit. You will need to pull the dishwasher out from the cabinet to reach it.
• Disconnect Connections: Carefully unscrew the brass water supply fitting and unplug the electrical solenoid wiring harness.
• Install the New Valve: Swap the old valve with a new OEM-certified replacement. Reconnect the wiring and water line, ensuring the brass fitting is snug but not over-tightened.
• Test for Leaks: Turn the water and power back on and run a short cycle to verify that the tub fills and drains correctly without any secondary leaks.

Recommended Replacement Valves

Since these valves cannot be cleaned or repaired once jammed, you will need a new assembly. The Bosch 00628334 Water Inlet Valve is the most common replacement for modern 300, 500, and 800 series models. It is a genuine part designed for a precise fit and reliable solenoid operation.

Repair Tip: When installing the new valve, avoid using teflon tape on the plastic threads of the valve itself, as this can lead to cracks. The brass fitting’s rubber seal should provide a sufficient watertight connection on its own.

A water inlet valve that is stuck in the open position causes water to get into the tub, even when the dishwasher is turned off.

Normally, water inlet valves get stuck in the open position whenever the solenoids got jammed by calcium build-up due to hard water.

Even if its small amount of water siphoning through the valve, in a couple of hours or on the next day you will see water level raised above fine filter mesh.

Water Not Filling Up Bosch Dishwasher

The fourth common problem associated with Bosch dishwashers is that water does not fill up the dishwasher. Like many of the other problems on this list, water not filling is caused by a faulty water inlet valve. To fix this problem, you can replace the water inlet valve.

If the inlet valve is defective it can close early, which prevents water from fully filling up the dishwasher during the cycle.

How to Replace a Bosch Dishwasher Water Inlet Valve

• Access the Valve: Remove the lower access panels at the front of the dishwasher to locate the valve assembly.
• Disconnect: Detach the wire harness, disconnect the water supply line, and remove the brass elbow from the old valve.
• Swap the Part: Remove the old water inlet valve and install the new replacement unit in its place.
• Reassemble and Test: Reconnect all lines and panels, then run a short cycle to ensure the “self-filling” issue is resolved.
• Solenoids: Use a multi-meter to check the solenoids.The solenoids are magnets that allow the water inlet valve to open and close. If the meter shows no continuity, it has failed and the valve cannot open or close properly.
• Since you’ll have the lower panel off anyway, check the drain pump nearby for any signs of small leaks or moisture, which could trigger a future E15 error.

Blinking Red InfoLight

The InfoLight is a helpful feature on many Bosch dishwashers that projects a red beam onto the floor to indicate a cycle is in progress. However, if this light is blinking, it usually signals a minor interruption rather than a major mechanical failure.

Common Reasons for a Blinking Red Light

• Door Not Fully Latched: The most frequent cause is a door that isn’t completely closed. If the latch doesn’t engage, the cycle will pause and the light will flash. Ensure no dishes are blocking the door and press firmly until you hear a click.
• Cycle Interruption: If the door was opened mid-cycle to add a dish, the light will blink to show the program is paused. To resume, simply close the door and wait a few seconds for the motor to restart.
• Refill Alerts: On some models, the light may blink or change behavior if the rinse aid or salt (for built-in softeners) is empty. Check your control panel for corresponding icons.
• Error Code Trigger: If the light is blinking in conjunction with an error code on the display (like E15 or E24), the machine has detected a fault like a leak or a drainage issue.

Cloudy Film on Dishes after Wash

Optical Water Sensor Calibration

Bosch uses an “AquaSensor” to measure how dirty the water is. If this sensor gets a film of grease or hard water on it, it will tell the dishwasher to skip the second rinse, leaving dishes with a cloudy film.

• The Maintenance Tip: Instead of a repair, this can often be fixed by running a “Heavy” cycle with a high-quality Dishwasher Cleaner to strip the film off the internal lens.

Common Bosch Dishwasher Error Codes

Related Read: All Bosch Dishwasher Error Codes – How To Enter Diagnostic Mode?

Frequently Asked Questions

What are Some Essential Maintenance Tools?

• For Hard Water Film: The Finish Dual Action Dishwasher Cleaner is specifically formulated to reach the hidden parts of the machine, including the AquaSensor lens and internal pumps.
• For Deep Cleaning: The Affresh Dishwasher Cleaner Tablets are excellent for monthly maintenance to prevent the grease buildup that causes E22 and E24 codes.

How do I reset a Bosch Dishwasher?

If the red light continues to blink and the door is clearly closed, try a Hard Reset. Turn off the dishwasher, wait 30 seconds, then hold the Start button for 3-5 seconds to clear the memory and restart the cycle from scratch.