The results of studying the hydrogen isotopes (H, D) yield of Ni, Pd, Pt, Ti, Zr metals with linear heating: a) by the accelerated electrons beam with energy up to 35 KeV, b) by joule heat of AC (50 Hz) through samples, c) by external coaxial furnace samples in metal (stainless steel) and d) quartz vacuum cells are presented. The highest temperature of the position of the maximum intensity hydrogen isotopes release at the linear heating corresponds to the samples heating in a metal vacuum cell, an external coaxial furnace. The lowest temperature position of the maximum intensity hydrogen isotopes release corresponds to the heating by accelerated electrons beam. The difference in these positions of the maximum is Delta T approximate to 350 degrees C. Difference in maxima position of the hydrogen and deuterium release into the low-temperature region is significant (Delta T approximate to 50-100 degrees C) for the Ni, Pd, Pt samples, and insignificant (Delta T <10 degrees C) for the Ti and Zr samples was found, when metals are heated by electric current or in a quartz vacuum cell compared to their heating in a metal vacuum cell. Possible mechanisms of non-equilibrium stimulation of the hydrogen isotopes release from metals, due to the accumulation of external energy by the hydrogen subsystem of crystals considered theoretically. The notions used wherein are in agreement with the obtained experimental results. (C) 2019 Hydrogen Energy Publications LLC. Published by Elsevier Ltd. All rights reserved.