3
Option 13 -- Room Air Temperature Offset
Selections:
±
5
_
F/
±
3
_
C. Default is 0.
The number of degrees to be added to the displayed temperature to
calibrate or deliberately miscalibrate the measured room
temperature. This option is in
_
F even if Option 3 is set for
_
C.
Step 4 — Understand Thermostat Operation
Temperature Display
Thermostat will display room temperature until UP or DOWN
button is pressed. The words SET TEMP appear when these
buttons are pressed and the current setpoint is displayed. If no
buttons are pressed for 5 sec, the display will change back to show
room temperature.
Backlighting
Continuous backlighting is not available. The backlight will come
on for 10 seconds after any button press. Without AC power and
when the battery is low, the backlight will remain off with button
presses.
Battery Indicator
A battery indication icon on the display shows nothing, half, or
low/no battery condition. If the battery is full or operation is from
AC power, no icon appears. Under battery operation, if the battery
is half full, a half full battery icon appears. As the battery depletes
below half, the icon remains at half, but the 10 second backlight
disappears. When the battery is absent or depleted, the display goes
blank except for an empty battery icon and all outputs are turned
off.
Timeguard Timer
A 5--minute timeguard is built into the thermostat immediately
upon power up, and any time the compressor turns off. The
compressor will not turn on until the timeguard has expired. The
timeguard affects only compressor operation. Pressing UP and
FAN buttons simultaneously will override the timeguard for 1
cycle. If PTAC operation (PH or PC) is selected under Option 1,
the timeguard timer is eliminated.
Cycle Timer
In normal heating and cooling operation the thermostat will not
allow more than 4 equipment cycles per hour (or 1 cycle every 15
minutes). Both the Y and W outputs have a 15--minute timer that
starts counting down when the output is turned on, (e.g., if Y
output is turned on for 9 minutes and then satisfies, it cannot turn
back on for another 6 minutes regardless of demand). However,
pressing UP and FAN buttons simultaneously or changing the
setpoint will override the timer for 1 cycle.
Minimum on Timer
Once the equipment has turned on, it will remain on for a
minimum of 3 minutes regardless of demand. However, the
equipment can turn off in less than 3 minutes if a change in
setpoint, or a change in mode occurs.
Staging Timer
If the thermostat is a heat pump model, it has 2--stage heat
capability. In normal operation there is a 15--minute delay between
the first and second stages of heat. The Y output will energize first,
then 15 minutes later, W is allowed to come on if the thermostat
determines it is not satisfying the demand.
However, if the heating demand is greater than 5
_
F/2.8
_
C, there
will be only a 30 second delay before bringing on W.
Auxiliary Heat Indicator
When operating a heat pump and either auxiliary heat or
emergency heat is active, a front mounted LCD indicates this
condition.
A07821
Error Messages
If the room temperature sensor fails, two dashes (----) will appear in
the temperature display and all heating and cooling outputs will be
turned off. The thermostat must be replaced.
If the internal non--volatile memory fails, E4 will alternately flash
with the temperature on the display and all heating and cooling
outputs will be turned off. The thermostat must be replaced.
Step 5 — Check Thermostat Operation
Fan Operation
1. Press FAN button. This will start continuous fan operation.
FAN ON icon will turn on.
2. Press FAN button again. This will stop continuous fan
operation. FAN ON icon will turn off.
Heating Operation
1. Press H/C button until HEAT is displayed.
2. Press UP button until LCD readout reads 3
_
F/1.7
_
C above
room
temperature.
Press
UP
and
FAN
buttons
simultaneously to defeat timers. Heating system should
begin to operate immediately.
3. For HP thermostats only, press H/C button until EMHT
(emergency heat) appears. Press UP and FAN buttons
simultaneously to defeat timers. Emergency heating (W is
ON, Y is OFF) should begin immediately.
Cooling Operation
1. Press H/C button until COOL is displayed.
2. Press DOWN button until LCD readout reads 3
_
/1.7
_
C
below room temperature. Press UP and FAN buttons
simultaneously to defeat timers. Cooling system should
begin to operate immediately.
Table 1 shows the thermostat outputs for each available stage of
heating or cooling. It may be useful in checkout or
troubleshooting.
T1
--
PA
C
/T1
--
PH
P
