Can be almost impossible to determine code without sighting receiver. Do you have old transmitter as the correct dip switch settings would be on this. One "trick" you can do if there are more than one remote fans installed is to check other controllers for their codes. generally when installers set dip switches for multiple fans in homes they move the No1 switch from 0 to 1 or vice versa, then the switch position for second fan is move switch 2 as previous. You may be lucky and "jag" the position otherwise you will need to get to receiver.