Zanussi ZDT 6053 not draining correctly

[streekie]

Hi,
I have a Zanussi ZDT 6053 from new.
I fitted it 2 years ago.
Always used the little finish washer tablets and rinse aid and wash all 3 filters in the sink once a week. I regularly (6 weekly) run their dishwasher cleaner through on a 70 deg cycle.
never used the salt dispenser as i believe the required substance is in the 3 in 1 tablets we use.
over the last couple of weeks the cleaning has not been up to scratch and noticed a blueish streaky coating on the inside of all metal surfaces. also when the flat plate filter is removed there is standing water in there and the salt dispenser in the base of the inside is also full of standing water.
is there an unblocker that can be run through without getting the machine un installed or if its not a blockage in the outlet pipe could it be something else like a sticking valve ?

many thanks

 

[zipper]

Look here http://www.dishwasher-care.org.uk/pdf/trouble.pdf
When the dishwasher is finished a cycle there is always a little water left standing in the sump....if it wasn't there you'd soon notice a very unpleasant smell in your kitchen. When you run a new cycle the first thing the machine does is pump out the stale sump water. It also normal for the salt reservoir to fill with water. There is no need to remove the dishwasher to perform any kind of maintenance

 

[Leccy758]

Do you check the spray arms for blockages in the water outlet holes.

 

[streekie]

turns out the clip securing the pipe to the wall had slipped allowing the pipe to drop about 1/2 in and now the appliance is pumping up hill hence the extra backflow into the sump once the pump has finished. cheers