Honeywell T8400C Support Question
Honeywell T8400C Support Question
Find answers below for this question about Honeywell T8400C.Need a Honeywell T8400C manual? We have 2 online manuals for this item!
Question posted by tearecs on January 15th, 2012
Temperature Display Blank
The thermostat display goes blank periodically.
Current Answers
Related Honeywell T8400C Manual Pages
Owner's Manual - Page 1
M18539
1
69-1490
69-1490 Set
Room
FAN Auto On
SYSTEM Cool Off Heat
M18535
Em Ht Aux Ht
Set
Room
Electronic Thermostat
OWNER'S GUIDE
FAN Auto On
SYSTEM Cool Off Heat Em.Ht.
Owner's Manual - Page 2
... need for you with a more comfortable and convenient living environment.
• Simple and easy to change your temperature settings are not required because your temperature setting.
• Large digital display. Congratulations on the purchase of this thermostat in an effort to provide you to use. The ▲ and ▼ keys make it easy for...
Owner's Manual - Page 3
...fan runs continuously. In heating, the fan may start a few minutes after
the heating equipment comes on the bottom of the thermostat case.
FAN Auto On
FAN SWITCH
M10273
3
69-1490 First set the FAN switch:
Auto: Normal setting for improved air
... settings are controlled by using FAN and SYSTEM switches located on .
In cooling, the
fan goes off and on with the cooling equipment.
Owner's Manual - Page 4
... heat, but your
equipment has failed or is on . Then set the SYSTEM switch:
Cool: Normal setting for months when your home
needs heating. Digital display
shows a snowflake when cooling is not working properly. Off:
Both heating and cooling are off. SYSTEM SWITCH
M10274
69-1490
4
Heat: Normal setting for months...
Owner's Manual - Page 6
... Room when the room temperature is displayed.
1. The temperature setting and the room temperature are shown separately on the digital display, press either the ▲ or ▼ key once.
Set
Room
INDICATOR
M18441
69-1490
6 To display the temperature setting on the digital display. The ▼ indicator points to Set when the temperature setting is displayed and to 37°...
Owner's Manual - Page 7
Set
Room
M18442
2. To lower the temperature setting, press the ▼ key.
Changing Temperature Setting
1. When in the cooling mode, raising the temperature before you leave for work or school also lowers your energy costs. When in the heating mode, lowering the temperature at night or during the day can lower your energy costs. To...
Owner's Manual - Page 8
... or school. If you like saving energy, but would like your thermostat to automatically change the temperature setting, you choose and your home, where you live, the number of energy saving periods you might want to automatically save energy with this thermostat, temperature settings can be conveniently programmed to consider purchasing the Honeywell Chronotherm®...
Owner's Manual - Page 9
... TO 18% 19 TO 22% 23 TO 33%
COOL
* YOUR SAVINGS DEPENDS ON HOME SIZE AND ACTUAL HEAT LOSS OR GAIN, GEOGRAPHIC LOCATION, FREQUENCY OF TEMPERATURES CHANGE, AND RANGE IN DEGREES OF CHANGE.
Owner's Manual - Page 10
... SYSTEM switch on .
See equipment manufacturer instructions. Heating or cooling does not come on the thermostat is below 50°F (10°C).
Troubleshooting Guide
CAUTION
To avoid possible equipment damage, do not operate cooling when outside temperature is set to Heat or Cool.
• Check the system fuse or circuit breaker and...
Owner's Manual - Page 11
For service, contact your local heating and cooling contractor:
11
69-1490
If you have questions concerning this thermostat, call Honeywell Customer Assistance at 1-800-468-1502, Monday-Friday, 7:00 am-5:30 pm, Central time.
Installation Instructions - Page 1
...Cooling cycle rate is selectable at 1, 3, 4, 5, 6, or 9 cph. T8400C and T8401C Electronic Thermostats
INSTALLATION INSTRUCTIONS
The T8400C and T8401C Thermostats provide singlestage, non-programmable temperature control for 24V heating-cooling systems with good air circulation at average temperature.
The T8400C Thermostat is a precision instrument and was carefully adjusted at the...
Installation Instructions - Page 2
... system controls and is adaptable to most 5-wire, 18 to 30 Vac heating-cooling systems. Refer to Fig. 5 and 6 for typical wiring hookups.
5-3/4 IN.
The T8400C Thermostat is acceptable. DECORATOR COVER PLATE
WALL
1 2
WALL ANCHORS (2)
Wiring
IMPORTANT Use an 18-gauge maximum wire for appearance. M11041C
Fig. 2. After wiring the wallplate, plug...
Installation Instructions - Page 3
... and SYSTEM Switches
Fan and system settings are : On: The fan runs continuously. When using the switches located at the top of the thermostat case. Mounting Thermostat to latch. T8400C/T8401C heat-cool wiring diagram in oil heating/electric cooling system. M18416
B PRESS LOWER EDGE OF
CASE TO LATCH. Use for most systems...
Installation Instructions - Page 4
... as follows:
Cool: The thermostat controls the cooling system. T8400C AND T8401C ELECTRONIC THERMOSTATS
Slide the FAN switch in the bottom left corner of the thermostat to select the desired system setting. Heat: The thermostat controls the heating system. Each press changes the setpoint one degree; The temperature setpoint is on display and to Room when the...
Installation Instructions - Page 5
... use only. When using an electric heat thermostat, the fan starts immediately.
3. A typical example is shown, but information displayed varies by the heating equipment and may cause compressor damage. T8400C AND T8401C ELECTRONIC THERMOSTATS
10. Press the t key to raise the temperature setting several degrees below the room temperature. Press the s key to Auto, if available...
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