I had the same code, 4 lights flashing which means overfilling but you've found that out ! If you can remove the right hand side panel you will see two pressure switches linked by a loop of plastic tube. This tube must be intact and a tight fit on each switch. If this is ok then the switches may be faulty.
Ken.D
April 2011
I have the same problem. Tripped the fuses. Any help would be appreciated...
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