Recently, a new type of a hydraulic temperature control technique, which was based on thermohydraulic characteristics of a pressure-controlled loop heat pipe (PCLHP), was suggested and proved its effectiveness in terms of the stability, precision, and predictability. However, the hydraulic operating temperature control of a PCLHP showed a temporary operation failure when a large-scale temperature increase was attempted with a rapid increase in the control gas pressure due to a possible pressure inversion between the evaporator and the compensation chamber. Although the PCLHP was soon recovered from the temporary instability, an accompanied sudden temperature drop made the hydraulic temperature control inadequate for applications where fast, large-scale, yet stable temperature controls were required. In this work, transient responses of the PCLHP to various increase rates of the control gas pressure were tested to obtain an optimum increase rate of the control gas pressure at which a large-scale temperature increase could stably be achieved without any instabilities. The tested pressure increase rates were from 25 Pa/s to 100 Pa/s, and the obtained optimum rate was 50 Pals for the tested PCLHP at 800 W. At this optimum rate of the control gas pressure increase, the PCLHP showed stable temperature increases with maximum increase rates of around 2 K/min whereas the control gas pressure increases at 100 Pals consistently resulted in temporary operation failures. Details on the experiments and the analyses on the obtained results were provided. (C) 2016 Elsevier Ltd. All rights reserved.