Heating System Table
Warm air, gas, or oil heating system with an efficiency rating under 90%.
(The furnace efficiency rating should be on the furnace.)
High-efficiency furnace such as a 90% or greater AFUE (Average Fuel
Utilization Efficiency) unit
Hot water boiler
Step 5. Wire Thermostat Terminals
END OF WIRE
Type of System
a. Hold thermostat as shown in Fig. 9.
b. Using the labels on the wires, match letter of your old ther-
mostat wire with the corresponding terminal on the back of
your new thermostat.
If letters on old thermostat terminals do not match letters on
new thermostat terminals, all old wires may not need con-
necting to new thermostat. See Special Wiring Instructions
Loosen terminal screws and slip each wire beneath its
matching terminal (Fig 10).
d. Securely tighten terminals.
1 and 2
Use factory setting