i keep getting an e24 error code on my bosch dishwasher, what does that mean and how do i clear it?

Diagnosis

The E24 error code on the Bosch 800 Series (SHPM88Z75N) is a specific "drain-and-fill" fault. Unlike a simple water supply issue, E24 typically triggers when the dishwasher attempts to fill with water but detects that the water level is not rising fast enough, or it detects that water is draining out of the tub as quickly as it is being pumped in. This creates a loop where the machine cannot reach the required operating volume within the timed window, causing the control board to trip the error to prevent the pump from running dry. This is most commonly caused by a partial blockage in the sump or a failure in the check valve (non-return valve). If the check valve is stuck open or fouled with debris, water flows backward into the drain hose during the fill cycle. Other common culprits include a clogged inlet filter at the water valve or a kinked drain hose that is creating a siphoning effect. You can confirm this by starting a cycle and opening the door during the fill phase; if you see very little water at the bottom of the tub despite hearing the inlet valve humming, you have a flow restriction.

How to Fix It

Follow these steps in order to clear the E24 code and restore proper water flow:

1. Clear the Sump and Filter: Remove the bottom rack. Rotate the cylindrical filter assembly counter-clockwise and lift it out. Remove the mesh filter and scrub it with a soft brush and dish soap. Reach into the sump area and feel for any hard debris (broken glass, fruit pits) that may be obstructing the impeller or the drain port.
2. Inspect the Non-Return Valve: Located in the sump area, there is a small rubber flap (the check valve). Use a flashlight to ensure it is seated correctly and not warped or obstructed by a foreign object. If it is stuck open, water will leak out while the machine tries to fill.
3. Clean the Inlet Valve Screen: Shut off the water supply valve under the sink. Unscrew the braided water line from the dishwasher's inlet valve. Use a needle-nose plier or a small pick to gently remove the small mesh filter screen located inside the valve port. Rinse it under high-pressure water to remove sediment and reinstall.
4. Check the Drain Hose High-Loop: Ensure the drain hose is not lying flat on the cabinet floor. It must be routed upward (looped) higher than the dishwasher's water level before connecting to the garbage disposal or sink drain. If it is too low, gravity will siphon the fill water out of the tub.
5. Hard Reset: Power down the unit at the circuit breaker for 60 seconds. Restore power and run a "Quick" cycle to verify the error is gone.

If That Didn't Work

• Replace the Water Inlet Valve: If the screen is clean but the machine still fails to fill, the solenoid on the inlet valve (Part #00654140) may have failed electrically. Test the solenoid for continuity using a multimeter; if it reads open, replace the entire valve assembly.
• Clear the Garbage Disposal Connection: If you recently installed a new garbage disposal, ensure the plastic knockout plug was removed from the disposal's dishwasher inlet. If the plug is still there, water cannot exit, but back-pressure can cause the sensor to trigger an E24 fault.
• Check for Air Locks: If the unit was recently moved or installed, air may be trapped in the lines. Disconnect the water line and run the tap for a few seconds to clear any air pockets before reconnecting the dishwasher line.
• Inspect the Pressure Switch/Sensor: The sensor that detects water levels may be fouled by grease or detergent buildup. Use a vacuum or compressed air to gently clear any residue from the pressure sensor port located near the sump.

Heads Up

• Avoid Over-Sudsing: Using non-dishwasher detergents or too much rinse aid can create foam that tricks the water level sensor into thinking the tub is full when it isn't, potentially triggering E-codes.
• High-Loop Maintenance: Periodically check the zip-tie or bracket holding your drain hose high against the wall; if it slips, you will experience intermittent E24 errors.
• Hard Water Warning: If you live in a hard water area, the inlet mesh filter can clog every 6-12 months. Clean it proactively to avoid pump strain.
• Drain Hose Kinks: When sliding the dishwasher back into the cabinet, ensure the drain hose isn't pinched against the wall, as this restricts flow and causes back-pressure faults.