Take a picture of the wiring
Take multiple pictures from different
angles to capture all of the letters
next to the terminals.
W or W1 (not in all systems)
Y or Y1
Be sure to include the terminal labels
and wires. You may need to reference
this image later.
Note: If you have wires connected to
2 R terminals, then you have a two-
transformer system. Call 1-855-733-
5465 to find a pro installer.