Over flow Float is full of water and needs to be manually emptied or somethings caught in the pump.
The following was found on another site and worked for our 500 series:
TURN POWER OFF before doing any of the below.
Full Thanks and acknowledgement to "Beaze"
".. my Dishlex Global 450 did show ‘oF’ display code. i.e.Unit overfilling. And pump running on with no control.
I have found that this ‘oF’ display code is caused by the drip tray at the very bottom (in the pump and motor cavity) filling up with water, floating a polystyrene float, which intern switches a micro switch.
In my case, Olive pips interrupting the discharge pump at the non return valve, which hindered its performance and caused the drip tray to catch the overflow water. (we found cherry seeds???)
The easiest way to remedy this is.
Inside the dishwasher, remove the left-hand wash filters etc at the bottom of the dishwasher. You will see on the left hand side ( at the bottom) a little black rubber thing. (Quite small) This is the top of the hinge to a rubber non-return valve. Remove the 3 x stainless screws with a Philips head screwdriver. Remove the bottom plastic grate. You will see the non-return valve slots into a vertical slot (remember this for the assembly)
You may need a torch? Stick your head right in the dishwasher and, you guessed it………...…….check to see if anything is in the suction pipe to the discharge pump. I found two olive pips.
You may need something smaller than your finger to scrap it out. And a small mirror?
The second thing is you need to remove the water out of the drip tray to reset the float switch. ... to get the water out of the drip tray ..remove the Right hand side panel.
Reach in with a sponge and remove the water bit by bit out of the small white oval shape drip tray.
The other way to remove (olive pips) etc from the discharge pump is to:
Remove the bottom front two panels. Remove the left hand side panel.
You will see the smaller sized discharged pump near the front left of the machine.
Looking from the front you will see one only small screw between the pump and the bottom of the dishwasher bowl.
Undo that screw and pull the pump out to the left.
You will see a largish pipe heading off from this pump to the back of the machine, and wire clamp arrangement (this is the discharge pipe) you will have to move this wire clamp up ( with a pair of pliers) to remove this pipe to gain access to the suction part of the pump (and the other side of the non return valve as describe prior).
The debris may wash out when the pump is removed.
This has an O ring type seal and therefore will seal again when assembled.
Hope this helps with the explanation in the manual which states “Contact service division” Remember TURN POWER OFF before doing any of the above. Have fun!!!!! Beaze"
worked for us, September 2008
