Symptoms
• Washing machine stops mid-cycle and displays E21 error code
• No water enters the drum at the start of the wash cycle
• Water fills very slowly or incompletely
• Cycle cannot proceed past the fill stage
• Machine beeps and locks after attempting to fill
• Display shows E21 and cycle halts
Possible Causes
• Kinked, pinched, or frozen inlet hose restricting water flow
• Clogged inlet filter screens (mineral buildup common in hard water areas)
• Faulty water inlet valve not opening properly
• Low household water pressure below 20 psi minimum requirement
• Closed or partially closed water shut-off valves behind the appliance
• Water level sensor malfunction preventing proper fill detection
• Internal water line blockage in the machine's plumbing circuit
• Defective door latch preventing cycle initiation and water fill
Safety Checks You Can Do
• Verify both hot and cold water shut-off valves behind the washing machine are fully open (turned counterclockwise)
• Check that inlet hoses are not kinked, twisted, or pinched along their entire length
• Inspect inlet hoses for visible cracks or splits and ensure connections are tight
• Unplug the machine, locate the inlet hose filters (small screens at the water connection points), and rinse them under running tap water to remove mineral deposits
• Test household water pressure at a nearby faucet to confirm it meets the 20-116 psi requirement for proper machine operation
• Ensure the washing machine door closes completely and latches securely
• Unplug the machine for 5 minutes, then plug it back in to perform a power reset
• Run a test cycle with no clothes and monitor if water fills normally
• Check your home's circuit breaker to confirm the outlet is not tripped
• If the machine is new or recently installed, confirm inlet hoses are compatible with your home's water connection type
• Contact Bosch customer support if error persists after completing these checks
Safety First
Always disconnect the appliance from power before performing any checks. If you are unsure about any step, please contact a qualified technician.