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 saDebora on July 22nd, 2014
My Honeywell Thermostat T8400c 1008 Is Blank Why?
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Current Answers
Answer #1: Posted by BusterDoogen on August 24th, 2014 11:58 AM
BusterDoogen
Member since:
October 30th, 2011 Points: 28,565,407
Member since:
October 30th, 2011 Points: 28,565,407
The T8400C Thermostat is powered through the heating/
cooling system controls and is adaptable to most 4-wire,
18 to 30 Vac heating-cooling systems.
The T8401C Thermostat is powered directly from the
system transformer and is adaptable to most 5-wire, 18
to 30 Vac heating-cooling systems. Since the display is powered by the H & A units power supply I suggest you pull the cover & base & check for loose wiring.
I hope this is helpful to you!
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Related Honeywell T8400C Manual Pages
Owner's Manual - Page 1
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. M18539
1
69-1490
69-1490
Owner's Manual - Page 2
Batteries are held permanently in an effort to provide you to use. Over 100 years of Honeywell engineering expertise went into the making of your temperature settings are not required because your new thermostat! You can easily read the current room temperature at a glance.
• No need for you with a more comfortable and...
Owner's Manual - Page 3
... controlled by using FAN and SYSTEM switches located on with the cooling equipment. In cooling, the
fan goes off and on the bottom of the thermostat case.
First set the FAN switch:
Auto: Normal setting for improved air
circulation and air quality.
Use for most homes. FAN Auto On
FAN SWITCH...
Owner's Manual - Page 8
... in the heating mode by raising the temperature setting during the day.
With this thermostat in the cooling mode by lowering the temperature setting 5°F (3°C) to 10...the day before you might want to consider purchasing the Honeywell Chronotherm® Programmable Thermostat. Energy Savings
You can save energy with this thermostat, temperature settings can be as high as 7% to...
Owner's Manual - Page 10
Temperature setting is too warm or cool.
• Check that the SYSTEM switch on .
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 ...
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.
Owner's Manual - Page 12
Registered Trademark
69-1490 J.H. 9-00
6ww9w-1.h4o9ne0ywell.com/yourhome
12 Honeywell Limited-Honeywell Limitée
1985 Douglas Drive North 35 Dynamic Drive
Golden Valley, MN 55422
Scarborough, Ontario M1V 4Z9
Copyright © 2000 Honeywell
All Rights Reserved
® U.S. Automation and Control Solutions
Honeywell International Inc.
Installation Instructions - Page 1
...thermostat, wallplate (for covering wallmarks.
See Fig. 1. This thermostat is a precision instrument and was carefully adjusted at 1, 3, 4, 5, 6, or 9 cph. T8400C and T8401C Electronic Thermostats
INSTALLATION INSTRUCTIONS
The T8400C and T8401C Thermostats... the system transformer. Registered Trademark Copyright © 2002 Honeywell •
• All Rights Reserved
69- 1480-...
Installation Instructions - Page 2
... desired decorator cover plate and the wallplate at the desired location on the wall.
2. Select the two mounting holes that best fit the application.
4. The T8400C Thermostat is acceptable. M11041C
Fig. 2. either method is powered through the wallplate entrance hole.
3.
Mounting decorator cover plate and wallplate to prevent electrical shock or equipment...
Installation Instructions - Page 3
... diagram in oil heating/electric cooling system.
PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
2 IN T8401C INSTALLATIONS, CONNECT C TERMINAL. See Fig. 8.
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
... no longer displayed.
69-1480-1
4 T8400C AND T8401C ELECTRONIC THERMOSTATS
Slide the FAN switch in the bottom right corner of the thermostat to select the desired system setting. To... 2.
Press the st keys simultaneously for approxi-mately five seconds as follows:
Cool: The thermostat controls the cooling system. M14681
4.
Change the SYSTEM switch setting to Set and flashes. ...
Installation Instructions - Page 5
...varies by the heating equipment and may cause compressor damage. When using an electric heat thermostat, the fan starts and stops with the heating equipment.
To change cooling algorithm to ... to display °C or °F. Press the s key. T8400C AND T8401C ELECTRONIC THERMOSTATS
10. Heating Cycle Rates.
NOTE: Steps 7 and 8 are available on most systems). Fan
1.
Installation Instructions - Page 6
Automation and Control Solutions
Honeywell
Honeywell Limited-Honeywell Limitée
1985 Douglas Drive North
35 Dynamic Drive
Golden Valley, MN 55422
Scarborough, Ontario
M1V 4Z9
69-1480-1 G.H. Rev. 2-02
www.honeywell.com/yourhome
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