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Replacement parts for FRIGIDAIRE GPDB998JC1 Frigidaire/dishwasher | AppliancePartsPros.com
Here is the tech sheet
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Problem is usually caused by a low fill level or dirty pump filters etc.
Most units fill to just under the heating element.
If it looks low add a couple quarts of hot water after the fill, just be careful to not overfill it.
If it now runs OK then the screen filter on the input side of the water valve is probably dirty.
Remove the valve from the machine and clean the screen filter.
Do not permanently remove the filter as it is there to keep crud out of the valve, which could hold the valve open and cause a flood.
Open up and check the pump/filters.