I have an XL14i Trane model 4TTX4048A. I am beginning to suspect the coil is undersized ( freezes in very hot weather ) or is one lacking a TXV/TEV. Unit was bought as a package with a gas furnace. The coil is Trane model RXC05453HPCO. Does anyone know if this coil should be sufficient for the condensing unit under most circumstances? Thanks.