What F8 Means
WHICH MACHINES THIS APPLIES TO: F8 exists on the DW20 platform only - the boards used in the machines sold in the US as the 3000 and 5000 Series. It is not in the DW70 fault table, and the current DBI, DFI and DSD machines do not use it either.
DW20 PLATFORM - WHAT F8 MEANS: the service manual reads "Blocked filter. The pressure sensor senses excessively low pressure during the final rinse. Indication after end of programme." During the final rinse the machine expects a particular water pressure in the system. When the filters are loaded with food waste the circulation pump cannot draw properly through them, the pressure the sensor sees drops below what it should be, and the control concludes the filters need attention.
WHAT THE MACHINE DOES NEXT: nothing is interrupted. The manual says the indication comes after the end of the programme, so the wash completes normally and the message is waiting when you open the door. On the DW20.4 and DW20.5 text panels it is spelled out: "Blocked Filter - The filter is clogged. See 'Cleaning the Filters'."
CLASSIFICATION: maintenance. This is the dishwasher asking for the routine cleaning its own manual describes, not a component failure, and the fix is in the owner's hands.
Common Causes of F8
- Coarse and fine filters loaded with food waste
- Filters refitted incorrectly so they do not seat
- Object lodged in the sump under the filters
- Pressure chamber partly blocked
- Pressure sensor reading low when the filters are in fact clear
🔧 One Safe Check You Can Try
Switch the dishwasher off at the outlet or the breaker first, so a programme cannot start while your hands are in the tub, and let the machine stand long enough that the water and the element are no longer hot - the filters sit in the sump where the wash water collects. Then lift out the coarse filter and the fine filter, which on this generation come out by hand without tools, and rinse them under a running tap with a soft brush until the mesh is open to the light rather than just looking clean. Check the sump underneath them for a seed, an olive stone or a shard of glass, and lift it out with a cloth rather than fingers. Refit both filters properly, making sure the coarse filter seats and locks, and run a hot programme. If the code returns after a properly cleaned set of filters, the pressure sensor or the pressure chamber is the next suspect and that is a service call rather than more cleaning.
⚠ Why You Shouldn't Go Further Than That
- Wash water and the heating element stay hot for a while after a cycle, so the machine needs time to cool before anything is lifted out of the sump.
- Broken glass collects in the sump and is not visible in dark water, which is why debris is lifted out with a cloth.
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.