Honeywell CT3300 warranty Wire the thermostat terminals, Heating system table

Heating system table

Note: Setting the screw “out one turn” means turning the screw 360° counter-clockwise, or one complete turn.

Type of system	Screws A and B	Fuel switch
Warm air, gas, or oil heating system with an efficiency rating under 90%.	Use factory setting	F
(The furnace efficiency rating should be on the furnace.)	A–leave in
	B–leave in
High-efficiency furnace such as a 90% or greater AFUE (Average Fuel	A–out one turn	F
Utilization Efficiency) unit	B–leave in
Hot water boiler	A–out one turn	F
	B–leave in
Electric furnace	A–leave in	E
	B–out one turn

Step 5. Wire the thermostat terminals

Fig. 9

G

Y

W

R

a.Hold the thermostat as shown in Fig. 9.

b.Using the labels on the wires, match the letter of your old thermostat wire with the corresponding terminal on the back of your new thermostat.

Fig. 10

5/16 in.

INSERT STRAIGHT

Note: If the letters on the old thermostat terminals do not match the letters on the new thermostat terminals, you might not need to connect all of the old wires to the new thermostat. See the wiring cross reference table on page 10 for details.

c.Loosen the terminal screws and slip each wire beneath its

M20125 matching terminal (Fig 10).

d.Securely tighten the terminals.

(8 mm)

UNDER

STRIP

SCREW HEAD

END OF WIRE VISIBLE HERE

M20126

69-0654-5 INSTALLATION 7