  The superconducting order parameter and LDOS spectra near an impenetrable
surface are studied on the basis of selfconsistent calculations for a two band
superconductor with nodeless extended s-+wave order parameter symmetry, as
possibly realized in Fe-based high-temperature superconductors. It is found
that for a wide range of parameters the spatial behavior of the order parameter
at a surface is not reduced to a trivial suppression. If the interband
scattering at a surface is of the order of the intraband one or dominates it,
it can be energetically favorable to change the symmetry of the superconducting
state near the surface from $s_{\pm}$ to conventional s-wave. The range of
existing this surface conventional superconductivity is very sensitive to the
relative values of interband and intraband pairing potentials. It is shown that
the LDOS spectra near the surface can qualitatively differ upon calculating
with and without taking into account the selfconsistency of the order
parameter.
