Are you sure that you don't just need a 30 vac external power transformer? I have found that this can be the culprit if you're not getting any power to the unit at all. You will have to trace your power supply wire back to the junction box where you should find the power transformer (usually) mounted to the outside of the junction box, or very close to it.

Terry, We just moved into a house with the same model. I know yours was an old post, but did you ever get a response from this forum or elsewhere?