Honeywell
Magic Stat
Microelectronic
HEATING OR HEATING/COOLING
THERMOSTAT
For most 24 V gas heating, oil heating and electric cooling control systems. Not
for multistage or heat pump systems.
INSTALLATION MANUAL
IMPORTANT
This thermostat
may be programmed either before or after installation. If programming before installation,
install a 9 V alkaline battery (purchase separately) in the thermostat, and refer to Owner’s Manual form
number 69-8026 for programming instructions.
Rev. 7-9o
Form Number 69-S025-2
Honeywell Inc. 1990
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PREPARATION
Your new thermostat is compatible with most
24 V furnace systems, and in most cases, should
not require additional accessories for proper opera-
tion. Table 1 lists the exceptions which require an
isolating relay or relay and transformer. Review
Table 1 to determine if your system requires the
accessory. If so, you may use the order form at the
end of this booklet. Detailed relay installation in-
structions are provided along with the accessory.
The isolating relay is a device used for heating
systems where the voltage in the control circuit is
interrupted during part of the furnace’s cycle, cut-
ting off power to the thermostat. The isolating relay
supplies the thermostat with a constant 24 volts,
eliminating any power interruptions to the thermo-
stat. The thermostat then receives its operating
voltage directly from the 24 V transformer, allowing
for operation of your thermostat.
Any questions concerning your system’s com-
patibility with your thermostat may be directed to
Honeywell Consumers Affairs at their toll-free
number, 1-800-468-1502.
1
69-802%2
