The weakest places of centralized heating systems are the pipelines. Heat pipe network systems, built in the USSR, are characterized by low reliability, high damage possibility and large heat losses. The main reasons for the heat losses growth are moisture, deformation and breakage of the thermal insulation layer. The purpose of this paper is to assess the extent of underground channel pipelines with strained thermal insulation layer heat losses, taking into account radiative heat transfer in the cavity of the channel. During the work the numerical analysis of thermal insulation layer deformation effect and radiation heat transfer in the cavity of the channel influence on thermal conditions and heat losses of underground channel pipelines was achieved. On the basis of these results the perspective of the developed model and numerical analysis techniques for the extent of pipelines with deformed thermal insulation heat losses evaluation was determined.