Which cycle are you using? The Normal Eco cycle doesn't fully fill with the selected temperature. It runs a reduced warm or hot for a brief time at start of the fill then switches to cold for the remainder of the fill to the selected level, that's part of the Eco aspect. If all the other cycles exhibit no hot or warm water (only a cold fill on those temp choices) then the hot inlet solenoid presumably is causing the problem. Have you checked for voltage at the solenoid and/or continuity on it (with power disconnected!) immediately when the problem is occurring? The control board may be the problem if no voltage is at the solenoid.