I have a similar delema. I want to replace a 6 wire Amana mercury stat with a Noma 5 wire programmable. The Amana has the following wires:

Green-W1
White-W2
Black-G
Red-RH
Red-RC
Orange-Y1

The Noma everything above but only 1 W wire. Can I use this stat. If so, how do I connect the W wires?

Wrong stat. The Amana has two-stage heat and you really would like to keep it for lower energy bills.