A method is provided for verifying integrity of a recirculation valve in a recirculation line of an LNG dispenser. The method includes: closing the recirculation valve and a fill valve in a supply line that supplies LNG; monitoring a mass of the LNG flowing through the recirculation line to ensure that the mass flowing therethrough is less than an acceptable threshold; and aborting any pending sales if the mass of the LNG flowing therethrough is not less than the acceptable threshold. According to another embodiment, a method is provided for verifying integrity of a vent valve in an LNG dispenser. The method includes: closing the vent valve and opening a fill valve in a supply line that supplies LNG; monitoring the pressure of the LNG within the fill hose to ensure that the pressure remains steady; and aborting any pending sales if the pressure does not remain steady.