1 68-0134
C.H. • 9-93 • ©Honeywell Inc. 1993 • Form Number 68-0134

The T8624C,D Chronotherm III Program-

mable Fuel Saver Thermostats provide auto-

matic control of multistage heating/cooling sys-

tems and offer users the highest standard of

comfort and convenience available with energy

savings.

■Different schedules may be selected for week-
days, Saturday and Sunday.
■Can be programmed in hand (with batteries in-
stalled) or on wall to provide up to four tempera-
ture settings per day.
■Large digital clock (liquid crystal display) indi-
cates continuous time, day, current period and
room temperature.
■Adaptive Intelligent Recovery™ brings room tem-
perature to programmed temperature at pro-
grammed time, maximizing comfort and energy
savings.
■Temperature control program maintains tempera-
ture within 1° F of setpoint.
■Temporary program override available by using:
—WARMER and COOLER keys.
—SKIP next period key.
—CHANGE to last period key.
■HOLD TEMP key provided for indefinite pro-
gram override (vacation/holiday).
■Installer self-test and time delay override save
installation time.
■SYSTEM light-emitting diode (LED) indicates
system is energized.
■Models available with automatic or manual heat/
cool changeover.
■Batteries included provide power to maintain
clock and memory during power failures.
■Switching subbase with wiring terminals included.
■Powered directly from control transformer, re-
quiring an extra (24V) wire to thermostat.
■Fan operation switch to select either independent
or direct thermostat control of fan in heating
included on back of select models.
CONTENTS
Specifications ................................................. 2
Ordering Information..................................... 2
Selection/Application .....................................4
Installation .....................................................5
Checkout....................................................... 11
Programming the Thermostat ......................14
Operating the Thermostat ............................18
Troubleshooting ...........................................21
Glossary ....................................................... 22
T8624C,D (5-1-1 Day
Programming) Chronotherm®
III Fuel Saver Thermostats