Honeywell T8400C 사용자 설명서

5

69-1480-1

3. Press the s key. Factory information is displayed. A 

typical example is shown, but information dis-
played varies by model. This information is for fac-
tory use only.

4. Press the s key again to display °C or °F.

5. Press the t key to change the °C or °F indication.

6. Press the s key to display the heat cycle rate of 1, 3, 

4, 5, 6, 9, or 12. If the desired cycle is displayed, 
press the s key to exit the installer setup mode. To 

change the heat cycle rate, press the t key to scroll 

between 1, 3, 4, 5, 6, or 9. Stop scrolling when the 
desired rate is displayed. See Table 1 for the cycle 
rate options and the corresponding system equip-
ment.

a

High efficiency furnace.

b

Refer to equipment manufacturer’s instructions.

NOTE: Steps 7 and 8 are available on select models.

7. Press the s key to display cooling algorithm config-

uration default.

8. Press the s key again to change cooling algorithm 

to C1 or C3.

C1 = Standard cooling algorithm.
C3 = Aggressive cooling algorithm (can cause 

overshooting).

9. Press the s key again. Current configuration (CC) is 

displayed. A typical example is shown, but CC varies 
by model. (This information is for factory use only.)

10. Press the s key to save all changes, exit installer 

setup mode and return to normal operation.

NOTE: After exiting installer setup mode, change the 

setpoint to the desired room temperature.

1. Slide the SYSTEM switch to Heat and the FAN 

switch to Auto, if available.

2. Press and hold the s key to raise the temperature 

setting several degrees above the room tempera-
ture. After approximately ten seconds, the heating 
equipment should start. In conventional systems, 
the system turns on the fan through the use of a 
time delay relay or through a limit control. When 
using an electric heat thermostat, the fan starts 
immediately.

3. Press the t key to lower the temperature setting 

below the room temperature. Heating equipment 
should stop.

Low Temperature Hazard.
Operating at too low of an outdoor 
temperature may cause compressor damage.
Do not operate cooling if outdoor temperature is 
below 50°F (10°C). Refer to manufacturer’s 
recommendations. 

1. Slide the SYSTEM switch to Cool and the FAN 

switch to Auto.

2. Press the t key to lower the temperature setting 

several degrees below the room temperature. After 
approximately five minutes, the cooling equipment 
should start. The fan starts and stops with the cool-
ing equipment.

3. Press the s key to raise the temperature setting 

above the room temperature. Cooling system 
should shut down.

NOTE: To bypass the 5 minute delay, see the Optional 

System Checkout section.

1. Slide the SYSTEM switch to Off and the FAN 

switch to On. The fan should run continuously.

2. Slide the FAN switch to Auto. In heating, the fan is 

controlled directly by the heating equipment and 
may start a few minutes after the heating equipment 
turns on (on most systems). When using an electric 
heat thermostat, the fan starts and stops with the 
heating equipment. In cooling, the fan starts and 
stops with the cooling equipment.

Make certain all equipment responds properly to the 
thermostat.

Steam, radiant floor heat, gravity

1

Hydronic heat, condensing gas 
furnace

a

3

Gas or oil forced air

6

Electric heat

9

Special applications

b

4, 5, 12

M14687

M14688

M14689

M14690

M18419A

M18420