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Honeywell T8400C Support Question

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Question posted by weinbower86 on January 27th, 2012

Thermostat Has Blank Screen, Heat Wont Work

i have no idea how to re set or get the thermostat to come on, just went blank sometime today while we were all at work or school.

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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

... 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. Over 100 years of Honeywell engineering expertise went into the making of your temperature settings are held permanently in an effort to provide you to use.

Owner's Manual - Page 3

... minutes after the heating equipment comes on with the cooling equipment. On: The fan runs continuously. Use for most homes. First set the FAN switch: Auto: Normal setting for improved air circulation and air quality. In cooling, the fan goes off and on . FAN Auto On FAN SWITCH M10273 3 69-1490 Settings Setting FAN and SYSTEM...

Owner's Manual - Page 4

... on . Digital display shows a flame when heating is not working properly. Em. SYSTEM SWITCH M10274 69-1490 4 Then set the SYSTEM switch: Cool: Normal setting for months when your home needs cooling (air conditioning). Off: Both heating and cooling are off. Heat: Normal setting for months when your home needs heating. Ht.: (Not available on all models.) Switch...

Owner's Manual - Page 5

... either Em Ht or Aux Ht when these modes are not available on all models. The ▲ indicator points to help handle the heating load. Em Ht: Aux Ht: The ▲ indicator points to Em Ht when the SYSTEM switch is set at Em Ht. Em Ht and Aux Ht Indications Emergency...

Owner's Manual - Page 6

...; to Room when the room temperature is displayed. 1. The ▼ indicator points to Set when the temperature setting is displayed and to 37°C). To display the temperature setting on the digital display. Set Room INDICATOR M18441 69-1490 6 The temperature setting and the room temperature are shown separately on the digital display, press either...

Owner's Manual - Page 7

... during the day can lower your energy costs. Changing Temperature Setting 1. To lower the temperature setting, press the ▼ key. Set Room M18442 2. To raise the temperature setting, press the ▲ key. Set Room M18443 7 69-1490 When in the cooling mode, raising the temperature before you leave for work or school also lowers your energy costs.

Owner's Manual - Page 8

... this thermostat in the cooling mode by lowering the temperature setting 5°F (3°C) to consider purchasing the Honeywell Chronotherm® Programmable Thermostat. Energy Savings You can save energy. 69-1490 8 If you like saving energy, but would like your home, where you live, the number of energy saving periods you leave for work or school.

Owner's Manual - Page 9

...10°F (5°C) DECREASE* 12 TO 18 TO 23 TO 25 TO UP TO 16% 22% 25% 29% 30% HEAT PERCENT OF COOLING COSTS YOU CAN SAVE SAVINGS FOR ONCE-A-DAY 10°F (5°C) INCREASE* 7 TO 9% 10 TO 11%... 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

... 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 or...the heating or cooling equipment. • Adjust the temperature by pressing either the ▲ or ▼ key. 69-1490 10 See equipment manufacturer instructions. Heating or cooling does not come on the thermostat ...

Owner's Manual - Page 11

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. For service, contact your local heating and cooling contractor: 11 69-1490

Installation Instructions - Page 1

...setpoints are held permanently by : - All TRADELINE® models include a thermostat, wallplate (for all models. Read these instructions. 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. Failure...

Installation Instructions - Page 2

... wallplate to prevent electrical shock or equipment damage. either method is adaptable to most 4-wire, 18 to 30 Vac heating-cooling systems. The T8401C Thermostat is powered directly from affecting the thermostat; T8400C AND T8401C ELECTRONIC THERMOSTATS YES NO NO 5 FEET [1.5 METERS] NO M10308 Fig. 1. DECORATOR COVER PLATE WALL 1 2 WALL ANCHORS (2) Wiring IMPORTANT Use an...

Installation Instructions - Page 3

... SUPPLY. Oil primary has its own transformer. Swing down the thermostat and press the lower edge of the thermostat case. Fig. 7. Use for most systems). Mounting Thermostat to latch. T8400C/T8401C heat-cool wiring diagram in oil heating/electric cooling system. OPERATION Setting FAN and SYSTEM Switches Fan and system settings are : On: The fan runs continuously. M11232...

Installation Instructions - Page 4

... Room INDICATOR ROOM TEMPERATURE SETPOINT TEMPERATURE M14679 To set the °F/°C indication and heat cycle rate: 1. M14685 2. TEMPERATURE DISPLAY Set Room INCREASE SETTING DECREASE SETTING FAN Auto On SYSTEM Cool Off Heat 3. Change the SYSTEM switch setting to select the desired fan setting. T8400C AND T8401C ELECTRONIC THERMOSTATS Slide the FAN switch in the bottom...

Installation Instructions - Page 5

...switch to display cooling algorithm configuration default. In heating, the fan is for factory use only.) CHECKOUT Heating 1. T8400C AND T8401C ELECTRONIC THERMOSTATS 10. Stop scrolling when the desired rate ... and the FAN switch to raise the temperature setting several degrees below the room temperature. When using an electric heat thermostat, the fan starts immediately. 3. Make certain ...