Troubleshooting - Honeywell CHRONOTHERM IV T8665A User Manual

TROUBLESHOOTING

Symptom
Display does not
come on.
Temperature setting
does not change
(Example: cannot set
the heating higher or
the cooling lower).
Heating does not
come on.
"Filter" flashes in
display.
Possible Cause
Thermostat is not being
powered.
The upper or lower
temperature limits were
reached.
System selection is not set to
Heat. Heating setpoint is
below room temperature.
Indicates a Filter Timer has
expired.
• Check if the batteries are correctly installed.
• Check if the thermostat is mounted and latched on the
wallplate—mount and latch the thermostat on the
wallplate.
Check that the temperature setpoints are:
Heating: 40 to 90°F (4 to 32°C)
Cooling: 55 to 99°F (13 to 37°C).
Check that setpoint is above room temperature.
Check if the circuit breaker is tripped—reset the circuit
breaker.
Check if the fuse at your fuse box is blown—replace the
fuse.
Check if the System switch at the equipment is in the
Off position—set to the On position.
Wait five minutes for the system to respond (thermostat
displays " Wait").
Set System selection to Heat.
See Display or Reset Filter Timer Settings section to
reset timer.
41
Action
continued
69-1536–3