Plasma heating by lower‐hybrid waves has been studied using a two‐and‐one‐half‐dimensional electrostatic code with more realistic plasma and source models than previously used. Mode couplings between wavenumber modes of opposite sign occur when two propagation cones meet. The resulting smallerk∥and/or higher &ohgr; modes propagate in the interior. These modes appear to be plausible mechanisms for tail heating of electrons and ions.