Honeywell ENERGYPRO T8665C Owner's Manual page 45

Symptom
Heating does not
come on.
Table 3. Troubleshooting. (Continued)
Possible Cause
The thermostat is part of a
Demand Response event.
No power to thermostat.
System selection is not set
to Heat.
Heating setpoint is below
room temperature.
If thermostat indicates SAVE, wait until
energy saving event is complete. To
cancel energy saving event, if available,
press and hold Run Program.
Check that setpoint is above room
temperature.
Check if circuit breaker is tripped—reset
circuit breaker.
Check if fuse at fuse box is blown—
replace fuse.
Check if System switch at equipment is in
Off position—set to On position.
Wait five minutes for System to respond
(thermostat displays "Wait").
Set System selection to Heat.
45
Action
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