Operating instructions

IV. THERMOSTAT OPERATION
A. Temperature Display
Thermostat will display room temperature until UP or DOWN
button is pressed. The word SET appears when these buttons are
pressed and the current set point is displayed. If no buttons are
pressed for 5 sec, the display will change back to show room
temperature.
B. 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.
C. 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 set
point will override the timer for 1 cycle.
D. 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 set
point, or a change in mode occurs.
E. 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°, there will be
only a 3-minute delay before bringing on W.
F. Error Messages
E4 will be displayed if the thermostat has an internal memory
failure. If E4 appears, replace thermostat.
-- (two dashes) will be displayed if the thermostat cannot properly
read room temperature. If -- appears, replace thermostat.
V. CHECK THERMOSTAT OPERATION
A. 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.
B. Heating Operation
1. Press MODE button until HEAT is displayed.
2. Press UP button until LCD readout reads 3° 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 MODE 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.
C. Cooling Operation
1. Press MODE button until COOL is displayed.
2. Press DOWN button until LCD readout reads 3° below
room temperature. Press UP and FAN buttons simulta-
neously to defeat timers. Cooling system should begin to
operate immediately.
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