What F40 Means
WHICH MACHINES THIS APPLIES TO: F40 belongs to the DW90 platform and to the current machines. The older DW20 and DW70 boards number the same fault F5.
DW90 PLATFORM - shown as F:40. The service manual is unusually detailed here: "Inlet valve leakage. Water intake detected when inlet valve deactivated in program sequence or standby. In this case the machine attempts to close the valve by opening it for 2 seconds and then closing it again. If water flow through the valve is still detected any current program is stopped (drain pump activated)." Note the phrase "or standby": the machine watches for this even when it is not washing.
CURRENT DBI, DFI, DSD AND DW60-SERIES MACHINES - shown as F40. The user manual names it "Inlet valve leakage" and its instruction to the owner is one sentence: turn off the water supply valve and contact service.
WHAT IS COMMON TO BOTH: the control switched the inlet valve off, then watched the flow meter and saw water still moving. The valve is not sealing, and the mains is connected to the inside of the dishwasher whether it is running or not.
CLASSIFICATION: fault, and the one on this platform with the clearest water-escape risk. It is the reason Asko's instruction starts with the tap rather than with the appliance.
Common Causes of F40
- Grit or scale on the inlet valve seat preventing it sealing
- Inlet valve diaphragm perished or the solenoid sticking open
- Flow meter reporting movement that is not happening
- Control or wiring fault leaving the valve energised
🔧 One Safe Check You Can Try
Turn off the dishwasher's water supply valve. That is Asko's own first instruction for this code and it is first for a reason: the valve inside the machine has stopped doing the job of shutting the water off, so the tap on the wall is now the only thing doing it, and the fault continues when the dishwasher is switched off and when nobody is home. Leave the tap closed until the machine has been repaired. After that, the useful work is looking rather than doing: check the cabinet floor in front of and under the machine and the underside of the worktop for damp, note whether there was standing water in the tub when you opened the door, and note whether the machine has been filling by itself between cycles. There is no owner adjustment to an inlet valve, and Asko's published instruction ends at shutting off the water and calling for service.
⚠ Why You Shouldn't Go Further Than That
- Mains water is live at the valve at all times and the fault does not stop when the dishwasher is switched off, so the supply tap has to be closed before anything else is considered.
- The inlet valve is at the back of the base and is reached by drawing the built-in machine out of its cabinet, which puts load on the very connection that is already failing.
- If water has reached the base tray it is sitting alongside the pump motors and the mains wiring, and moving the machine spreads it across them.
Opening a panel to inspect or repair something yourself doesn't automatically cancel your manufacturer's warranty — but it can risk accidental damage, and some manufacturers do have specific service conditions. Check your product's warranty terms, or ask us, before deciding.