I have a new Englander 25EP, that is less than 2 months old, which has developed a whine coming from the convection blower. Changing blower speed sometimes temporarily eliminates the noise. Other times it doesn't. It is more noticable at higher speeds. Has anyone had a simular problem ? Is there a simple fix ? Can the fan be lubricated ? Other than the whine, the stove has performed flawlessly.