Honeywell RTH7400D Owner's Manual page 13

Step 6. Mount New Wallplate to Wall (Cont)
3. Position the wallplate on the wall with the arrow
pointing up. Level the wallplate (for appearance
only) and mark the two mounting holes with
a pencil.
LEVEL
WALLPLATE
M22292
13
PLACE LEVEL ON
SUPPORT TABS
MARK
MOUNTING
HOLES (2)
69-1726—1