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Specifications, Troubleshooting – White Rodgers EMERSON 1.00E+78 User Manual

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4

Symptom

Possible Cause

Corrective Action

No Heat

(common problems)

Blown fuse or tripped circuit breaker.

1.

Furnace power switch to OFF.

2.

Furnace blower compartment door or panel

3.

loose or not properly installed.

Replace fuse or reset breaker.
Turn switch to ON.
Replace door panel in proper position to engage safety interlock or door switch.

No Heat

Pilot light not lit.

1.

SYSTEM Switch not set to

2.

HEAT.

Loose connection to thermostat or system.

3.

Furnace Lock-Out Condition. Heat may also be

4.

intermittent.

Heating system requires service or thermostat

5.

requires replacement.

Re-light pilot.
Set SYSTEM Switch to

HEAT and raise temperature above room temperature.

Verify thermostat and system wires are securely attached.
Many furnaces have safety devices that shutdown when a lock-out condition

occurs. If the heat works intermittently contact the furnace manufacturer or local

service person for assistance.
Diagnostic: Set SYSTEM Switch to

HEAT and raise the setpoint above room

temperature. Within a few seconds the thermostat should make a soft click sound.

This sound usually indicates the thermostat is operating properly. If the thermo-

stat does not click, try the reset operation listed above. If the thermostat does not

click after being reset contact your heating and cooling service person or place of

purchase for a replacement. If the thermostat clicks, contact the furnace manufac-

turer or a service person to verify the heating is operating correctly.

Heat, Runs

Constantly

Possible short in wiring.

1.

Possible short in thermostat.

2.

Possible short in heat system.

3.

Check each wire connection to verify they are not shorted or touching together.

No bare wire should stick out from under terminal screws. Try resetting the

thermostat as described above. If the condition persists the manufacturer of your

system or service person can instruct you on how to test the Heat system for

correct operation. If the system operates correctly, replace the thermostat.

Furnace Cycles Too

Fast or Too Slow

(narrow or wide

temperature swing)

The location of the thermostat and/or the

1.

size of the Heating System may be

influencing the cycle rate.

Digital thermostats normally provide precise temperature control and may

cycle faster than some older mechanical models. A faster cycle rate means the

unit turns on and off more frequently but runs for a shorter time so there is no

increase in energy use. If you would like to increase the cycle time, clip Jumper

W-905 as mentioned in the instructions for Hydronic Heating Systems. It is not

possible to shorten the cycle time. If an acceptable cycle rate is not achieved

as received or by clipping W-905 contact a local service person for additional

suggestions.

Thermostat Setting and

Thermostat Thermometer

Disagree

Thermostat thermometer setting requires

1.

adjustment.

The thermometer can be adjusted +/- 3 degrees. See Temperature Display

Adjustment in the Operation section.

Blank Display and/or

Keypad Not Responding

Voltage spike or static discharge.

1.

Battery change required.

2.

Replace batteries and check heat/cool system for proper operation. If a voltage

spike occurs use the Reset Operation listed above.

ELECTRICAL DATA
Electrical Rating:
0 to 30 VAC 50/60 Hz. or D.C.
0.05 to 1.0 Amps (Load per terminal)
1.5 Amps Maximum Total Load (All terminals combined)

THERMAL DATA
Setpoint Temperature Range:
45°F to 90°F (7°C to 32°C)
Operating Ambient Temperature Range: 32°F to 105°F
Operating Humidity Range: 0 to 90% RH (non-condensing)
Shipping Temperature Range: -40°F to 150°F

Reset Operation
If a voltage spike or static discharge blanks out the display or
causes erratic thermostat operation you can reset the thermostat
by pressing

and

at the same time while moving the

SYSTEM switch from

OFF to HEAT. This also resets the factory

defaults. If the thermostat has power, has been reset

and still does not function correctly contact your heating/cooling
service person or place of purchase.
Batteries
For optimum performance, we recommend replacing batteries
once a year with fresh “AAA” Energizer

®

alkaline batteries.

6

SPECIFICATIONS

7

TROUBLESHOOTING

White-Rodgers is a division
of Emerson Electric Co.

The Emerson logo is a
trademark and service mark
of Emerson Electric Co.

Homeowner Help Line: 1-800-284-2925

www.white-rodgers.com

www.emersonclimate.com