Filter plugging can have several causes. Low temperatures cause waxes that are part of the fuel solution to crystallize (AKA-cloud point), which can lead to filter plugging. An example would be using summer diesel in cold weather. Wax or paraffin is part of the diesel fuel. Cold temperatures cause the wax to turn into crystals. These crystals stop the flow of fuel through the filter. A use of an anti-gel or heated filter will help with this problem.
Chemical incompatibility may cause dramatic filter plugging. This may happen when fuels with incompatible additive packages are mixed.
Contaminant build up resulting from excessive microbial growth and bio-degradation of fuel can cause filter plugging. Micro-organisms, bacteria and