The system "mode" is selected by pressing the SYSTEM the room temperature is 70° with the equipment using only the
button. Icons on the bottom right corner of the display will first stage of heat. Since the equipment is keeping the tempera-
indicatethemode: COOL( ), AUTO(
), HEAT ( ),EMER, ture within 1° of setpoint, the thermostat will delay second stage
or OFF. In any mode except OFF, the setpoint temperature will for a longer time if you manually raise the temperature or if the
be shown on the right side of the display. In OFF, this area will room temperature quickly changes. Once the second stage
be blank. The current temperature will be displayed on the left comes on, it will come on sooner the next time there is a
side of the display.
difference between the setpoint and the room temperature. The
net effect of the staging program is that when the first stage is
capable of making temperature the second stage will delay
longer. When the thermostat calculates that first stage cannot
make temperature in a reasonable time, the second stage will
come on sooner. This built in function automatically optimizes
the use of additional stages of heat or cool.
To operate properly in the AUTO mode, the heat setpoint
temperature cannot be the same as or higher than the cool
setpoint temperature. The heat setpoint must be at least 1°
lower than the cool setpoint.
Automatic System Changeover
When the thermostat is in the AUTO mode, both theFlame and
Snowflake icons are displayed. The thermostat will call for heat
or cool depending on the room temperature. The setpoint
temperature displayed will be that of the last mode called. If the
lastsystemcyclewasheat, the HEAT setpointwillbedisplayed.
COOL setpoint and a call for cool is required, the temperature
displayed will change to be the COOL setpoint.
LOW BATTERY INDICATOR
the display will be blank except for “
LO BATT”. We recom-
mend replacing batteries every 2 years. If the home is going
to be unoccupied for an extended period (over 3 months),
the batteries should be replaced before leaving. When the
batteries are low, pressing any button will cause the display
tooperatedfortenseconds. Aftertenseconds, thedisplaywill
be blank except for “LO BATT”. You cannot program with low
batteries, but you can override setpoint temperature. After
Second Stage Time Delay
Your thermostat is designed to determine the optimum time to
activate the second stage. Simply raising the temperature in
heating or lowering it in cooling will not always force the
thermostat to bring the second stage on quickly. There is a time
delay from 0-30 minutes depending on the performance of the
first stage of the system.
LO BATT” has been displayed for 4 weeks, the thermostat
will raise the temperature 10 degrees above your setpoint in
COOL mode and will drop the temperature 10 degrees below
your setpoint in HEAT mode. If the “LO BATT” condition
continues, and when it reaches certain value, the thermostat
will turn off all the loads and “LO BATT” will flash.
EXAMPLE: For the last 2 hours the thermostat is set on 70° and
If a voltage spike or static discharge blanks out the display or causes erratic thermostat operation, you can reset the thermo-
stat by removing the wires from terminals R and C and removing batteries for 2 minutes. After resetting the thermostat,
replace the wires and batteries. If the thermostat has been reset and still does not function correctly, contact your heating/
cooling service person or place of purchase.
No Heat/No Cool/No Fan
1. Blown fuse or tripped circuit breaker.
2. Furnace power switch to OFF.
Replace fuse or reset breaker.
Turn switch to ON.
. Furnace blower compartment door or
panel loose or not properly installed.
Replace door panel in proper position to engage
safety interlock or door switch.
1. Pilot light not lit.
. SYSTEM button not set to HEAT.
Press SYSTEM button to HEAT and raise setpoint
above room temperature.
Verify thermostat and system wires are securely
Many furnaces have safety devices that shut down
when a lock-out condition occurs. If the heat works
intermittently contact the furnace manufacturer or
local service person for assistance.
. Loose connection to thermostat or
. Furnace Lock-Out Condition. Heat
may also be intermittent.