White Rodgers 1F78H - Manual (Page 7)

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Symptom Possible Cause Corrective Action
No Heat/No Cool/No Fan 1. Blown fuse or tripped circuit breaker. Replace fuse or reset breaker.
(common problems) 2. Furnace power switch to OFF. Turn switch to ON.
3. Furnace blower compartment door or Replace door panel in proper position to engage
panel loose or not properly installed. safety interlock or door switch.
No Heat 1. Pilot light not lit. Re-light pilot.
2. System Switch not set to Heat. Set System Switch to Heat and raise temp above
room temp.
3. Loose connection to thermostat or system. Verify thermostat and system wires are securely
attached.
4. Furnace Lock-Out Condition. Heat may also Many furnaces have safety devices that shut
be intermittent. down when a lock-out condition occurs. If the
heat works intermittently contact the furnace
manufacturer or local service person for
assistance.
No Heat (continued) 5. Heating system requires service or Diagonistic: Set System Switch to Heat and raise
thermostat requires replacement. the setpoint above room temperature. Within a few
seconds the thermostat should make a soft click
sound. This sound usually indicates the thermo-
stat is operating properly. If the thermostat 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 manufacturer or a
service person to verify the heating is operating
correctly.
No Cool 1. System Switch not set to Cool. Set System Switch to Cool and lower temp below
room temp.
2. Loose connection to thermostat or system. Verify thermostat and system wires are securely
attached.
3. Cooling system requires service or Same procedure as diagnostic for No Heat
thermostat requires replacement. condition except set the thermostat to Cool and
lower the setpoint below the room temperature.
There may be up to a five minute delay before the
thermostat clicks in Cooling.
TROUBLESHOOTING
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 TIME at the same time. 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.
9
ELECTRICAL DATA
Electrical Rating:
20 to 30 VAC 50/60 Hz.
0.05 to 1.2 Amps (Load per terminal)
1.5 Amps Maximum Total Load (All terminals combined)
SPECIFICATIONS 8
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