Clean an oil tank whistle by pouring 8 ounces of an oil tank solvent, such as Fuel Right, into the vent pipe to soften and break down whatever is clogging the whistle. Then, after waiting two days, pour half a gallon of paint thinner or mineral spirits down the vent line to wash away any leftover clogs and clear away the solvent.
Oil tank whistles are in place to whistle when an oil tank is full so that the tank doesn't overflow and spill oil. Oil tank whistles are typically placed in the vent pipe just above the oil tank. New oil poured into the tank displaces air. When the extra air exits out the vent pipe, it blows the whistle. When the whistle stops blowing, the oil tank is full.
Oil tank companies that fill oil tanks will not fill tanks that do not have a functioning whistle, because oil spills are dangerous for humans and the environment. Therefore, it is imperative to have a clean and functioning oil tank whistle in order to have a full oil tank.
Due to the dangers of oil spills, it is safer to hire certified professionals to clean oil tank whistles. Hiring a professional saves time and protects oil tanks from damage.