Boronization of the vacuum chamber of the L-2M stellarator has resulted in modification of the electron temperature profile. In particular, a well-defined jump in the electron temperature to Te ∼ 100 eV in a narrow region Δr/r ∼ 0.05 is observed in the temperature profile at the plasma edge. In the present paper, the value and shape of the jump in Te are studied at different values of plasma parameters and ECR heating power. A jump in Te is absent at a power of P ∼ 100 kW, whereas at P ∼ 200 kW the electron temperature drops from 150 eV to zero within Δr ∼ 0.5 cm. The value of threshold power for the formation of a jump in Te at ne ∼ 1.7 × 1019 m−3 lies within the range P ∼ 100–160 kW. In terms of power per particle this power threshold is P/V/Ne ∼ 0.2–0.3 Mw/m3/1019m−3, the value of which coincides with threshold power for ETB formation found recently in the CHS stellarator. When the helical-field strength is 25% or 50% below its standard value, a jump in Te at the plasma edge in L-2M is absent.