85 300 heater problem??
 

When cold in the am, heater button to left of off button pushed in,--doesn't come on. Only way I can get it to come on is by pushing the fourth button over or the defrost button. Once it starts, I can then push the first left of the off button and it will continue operating. Middle button sometimes makes it come on, but not always.
Put a new monovalve in and the heat part is fine.
Thanks for any help.