Gelled Heating Oil Troubleshooting

When the first cold snap occurs each year we receive calls that fuel has frozen or gelled. Over the years we have done detailed investigations on several instances including fuel analysis and product treat ratios. There are several possibilities.

Proper Treat Ratio Was Not Achieved

The recommended ratio is 1:2200 or one 16 oz. bottle per 275 gallons. Our ratios are based on having a cloud point of +15°F. Fuel oil varies from area to area and even batch to batch, and can have a cloud point of 20-25 even well above 30°F, depending upon the wax content of the base oil it is derived from. If your particular fuel has a higher cloud point, it requires a higher treatment ratio. It can be 1:1000 or, in rare instances, even 1:500. It is important to remember that even if you are bulk treating fuel correctly, and you add 750 gallons to a 1000 gallon tank, you’re still left with 250 gallons of untreated fuel. Outside air temperature is also certainly a factor.

Product Was Not Properly Mixed with Fuel

In our experience, this is the number one reason for gelling while using our product. Human nature being what it is, people tend to wait until the last possible moment or beyond to treat their fuel. Often when they finally do treat, they pour cold additive into cold or already gelled fuel, expecting it to work. These products require thorough mixing to work properly. Ideally, HOT 4 in 1 should be added before or as fuel is being added to the tank. This applies to bulk, trucks or location tanks. 

Product Was Added to Very Cold Fuel

HOT is heavier than fuel. At temperatures near 0°F, it will thicken and the product will develop a white haze. This is normal. When properly mixed with the fuel, the anti-gel will function as designed. If it is not properly mixed, it will sink to the bottom and will take a long time to mix completely.

  • Cloud Point — The temperature at which sufficient wax crystals begin to form in fuel.        
  • Cold Filter Plug Point — The temperature at which sufficient wax crystals have formed to block the flow of fuel through a filter. The cold filter plug point in un-treated fuel is typically two to five degrees below the cloud point.
  • Pour Point — The temperature at which fuel will no longer pour.