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 greenpenny15 on January 18th, 2021
I Can't Get The To Read
I took the faith off to clean it now and won't read the digital temperature
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
... for batteries. You can easily read the current room temperature at a glance.
• No need for you with a more comfortable and convenient living environment.
• Simple and easy to change your temperature setting.
• Large digital display. Batteries are not required because your new thermostat! Congratulations on the purchase of this thermostat in memory.
69-1490...
Owner's Manual - Page 3
...-1490
Settings
Setting FAN and SYSTEM Switches
Fan and system settings are controlled by using FAN and SYSTEM switches located on the bottom of the thermostat case. On:
The fan runs continuously. First set the FAN switch:
Auto: Normal setting for improved air
circulation and air quality.
Owner's Manual - Page 4
SYSTEM SWITCH
M10274
69-1490
4 Digital display shows a flame
when heating is not working properly. SYSTEM Cool Off Heat Em.Ht.
Off:
Both heating and cooling are off.
Heat: ... but your
equipment has failed or is on . Em. Then set the SYSTEM switch:
Cool: Normal setting for months when your home
needs heating.
Digital display
shows a snowflake when cooling is on .
Owner's Manual - Page 6
... 99°F (5° to Room when the room temperature is displayed and to 37°C). The ▼ indicator points to Set when the temperature setting is displayed.
1. To display the temperature setting on the digital display.
The temperature setting and the room temperature are shown separately on the digital display, press either the ▲ or ▼ key...
Owner's Manual - Page 7
...
M18443
7
69-1490
When in the cooling mode, raising the temperature before you leave for work or school also lowers your energy costs. To raise the temperature setting, press the ▲ key. Set
Room
M18442
2. When in the heating mode, lowering the temperature at night or during the day can lower your energy...
Owner's Manual - Page 8
... work or school.
Savings can be conveniently programmed to automatically save energy.
69-1490
8 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 33% depending on your...
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.
M10278
9
69-1490
Owner's Manual - Page 10
...equipment manufacturer instructions.
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 replace ... power to the heating or cooling equipment.
• Adjust the temperature by pressing either the ▲ or ▼ key.
69-1490
10 Heating or cooling does ...
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
...unheated (uncooled) areas such as provided in the trash. Temperature indication can be affected by non-volatile memory for covering wallmarks.
INSTALLATION
When Installing this control is powered directly from heat to cool. Read these instructions. Disconnect power supply before installation. The T8400C Thermostat is a precision instrument and was carefully adjusted at the...
Installation Instructions - Page 2
...
Fig. 1.
See Fig. 3.
1 3-7/8 IN. DECORATOR COVER PLATE (SELECT MODELS).
2 DRILL 3/16 INCH HOLES (IF DRYWALL) OR 7/32 (PLASTER OR WOOD)
WHEN USING WALL ANCHORS. The T8400C Thermostat is powered through the heating/ cooling system controls and is adaptable to most 5-wire, 18 to 30 Vac heating-cooling systems. Refer to the shaded...
Installation Instructions - Page 3
... system with gas heat/electric
cooling. Oil primary has its own transformer. M18416
B PRESS LOWER EDGE OF
CASE TO LATCH. Use for most systems). T8400C AND T8401C ELECTRONIC THERMOSTATS
KEEP WIRING IN SHADED AREA
ALTERNATE MOUNTING SCREW HOLE
W
Y G
R C
MOUNTING SCREW HOLE
ALTERNATE MOUNTING SCREW HOLE
WIRING ENTRANCE HOLE
MOUNTING SCREW HOLE
M11023...
Installation Instructions - Page 4
... SYSTEM switch in the lower right corner of the thermostat to turn heat or cool outputs on , the t key turns it on . T8400C AND T8401C ELECTRONIC THERMOSTATS
Slide the FAN switch in the bottom left corner of the thermostat to 52°F. If the temperature is on the digital display, press either the s or t key once...
Installation Instructions - Page 5
...Operating at too low of 1, 3, 4, 5, 6, 9, or 12. Cooling system should stop.
T8400C AND T8401C ELECTRONIC THERMOSTATS
10. Press the s key again to lower the temperature setting below the room temperature.
Refer to raise the temperature setting above the room temperature. Fan
1. After approximately ten seconds, the heating equipment should start .
When using...
