The loop heat pipe (LHP) is known to have a lower limit on input power. Below this limit the system may not start properly creating the potential for critical payload components to overheat. The LHP becomes especially susceptible to these low power start-up failures following diode operation, intentional shut-down of the device, or very cold conditions. These limits are affected by the presence of adverse tilt, mass on the evaporator, and noncondensible gas in the working fluid.