Honeywell T8665C Thermostat User Manual


 
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Heat Pump Fault Monitor LED lights red when
heat pump failure is
detected. Switch thermostat
to Em. Ht. and contact you
heat pump service com-
pany. Heating with Em. Ht.
is expensive, so act quickly.
Successful Communication Indicator
The thermostat periodically sends and receives
messages. The small triangle right of the
temperature display indicates the thermostat
successfully communicated with the system
controller installed by your Energy Utility.
PROGRAMMING YOUR
THERMOSTAT
7-Day Program and Operation
Your thermostat is 7-day programmable, which
means you can set your thermostat for four
periods (Wake, Leave, Return and Sleep) and
up to eight temperatures (four Heat and four
Cool) for each day of the week. Each day can
be the same or different.
M1776
3
Mon
System
Fan
Hea
t
Auto
AM
Heat
Temporary
HEAT PUMP