Prevents waxing of the diesel fuel at low temperatures.

At low temperatures, diesel fuel precipitates paraffin crystals that are normally suspended in the fluid.  As their concentration increases, the fuel filter will clog and ultimately the engine will stall.

Additives to diesel fuel that counter this effect are expensive, frequently unsatisfactory, and in some cases environmentally harmful as well as dangerous.  The addition of fuel additives to winter grade diesel only slows the process of crystals forming, but when they appear, are much larger in size.  However, one thing is certain: once the paraffin crystals have formed, they can only be cleared by the addition of heat.

The answer to this problem is ThermoLine, a diesel fuel pre-heating system that can be inserted into the fuel line to melt the paraffin crystals before they can reach the primary filter.