wiring with theses things is not always straight forward although if you order a control unit that does the same functions as the original one you have then wiring will more likely be the same or at least the same amout of connections inside! and if you order the same make then u have even more chance to that it will be a straight swop, best thing to do when you remove old unit is to check on the back of the unit what each wire does and match to new wiring diagram of new programmer, as most programmers tell you what each connection does or atleast has a code which in turn you can find out what each one is for, ie, heating on heating off etc etc. but if the above model is correct you may well be able to connect onto original back plate without adjusting the wiring, w