Digital Thermostat
Owners Manual
Model: PS2110 Series
Your new thermostat will provide years of reliable service
and will create uniform comfort in your home through the
seasons. Thank you for buying the product!
Please read this manual for complete instructions on
installing and operating your thermostat. If you require
further assistance, please feel free to contact us.
IMPORTANT INFORMATION
1. This thermostat is designed to work on the following
systems:
• Gas – Standing Pilot
• Oil – Fired Furnace
• Gas – Electronic Ignition
• Single Stage Heat Pumps
– with no auxiliary heat
• Gas – Fired Boilers
• Electric Furnace
• Gas – Millivolt Systems
• Electric Air Conditioning
• Oil – Fired Boilers
This thermostat will NOT control multistage heat pumps or
110/220V baseboard electric heating systems.
2. Temperature Range
This thermostat can be set between 45°F and 95°F (7°C
and 35°C). However, it will display room temperatures
from 30°F to 99°F (0°C and 37°C). HI will be displayed if
the temperature is higher than 99°F (37°C), and LO will be
displayed if the temperature is lower than 30°F (0°C).
This thermostat will automatically shut down in Heat
mode if the temperature rises above 95°F (35°C), and will
automatically shut down in Cool mode if the temperature
drops below 45°F (7°C).
3. Compressor Protection
This thermostat provides a 4 minute delay after shutting
off the compressor before it can be restarted. This feature
will prevent damage to your compressor caused by rapid
cycling. It does not prevent a rapid compressor restart due
to short power outages.
4. Battery Warning
Two fresh AA alkaline batteries should provide well over
one year of service. However, when the batteries become
weak the Low Battery Indicator will flash on the display.
When this message occurs, install new alkaline batteries.
You have approximately 1 minute to change the batteries
and keep the thermostat’s settings. Once the batteries
have become too weak to ensure proper operation, your
system will be turned off, and the display will be cleared
except for a flashing Low Battery Indicator on the LCD
display.
CAUTION: When only the battery icon flashes on the
display, the thermostat is shut down, and your system
will no longer operate. In this condition, there is no
temperature control.
NOTE: The backlight will not function when the thermostat
is in low battery condition.
NOTE: If you plan to be away from the premises over 30
days, we recommend that you replace the old batteries
with new alkaline batteries prior to leaving.
by Uni-Line®
FEATURES
Structure of thermostat and explanation of the keypads
OPERATION
Start-up
The LCD will show the factory default
display of 70°F (21°C) when batteries
are first installed. The temperature will
update after a few seconds.
System Switch
The System switch on the front of the
thermostat determines the operating
mode of the thermostat. You may select
COOL, OFF, or HEAT.
NOTE: Anytime you install or remove the thermostat from
the wallplate, slide the System switch to the OFF position
to prevent the possibility of a rapid system On – OFF.
Fan Switch
The Fan switch should normally be set in
the AUTO position. The Fan will turn on
during normal operation of your system.
In a normal gas or oil furnace, the Fan
will turn after the furnace warms up. For electric heat, air
conditioning, and heat pump operation, the Fan will turn
on with the system.
To run the Fan continuously, slide the Fan switch to the
ON position.
Review Current Set Temperature
• Press either the up or down key once to see the Set
Temperature.
The factory default is 68°F (20°C) when started with the
System switch on Off or Heat, and 78°F (26°C) when
started with the System switch on Cool.
Setting New Temperature
• Press either up or down once to
display the set temperature.
• Press either up or down again
to change to your desired Set
Temperature. Hold the key down for over 2 seconds to
fast advance the Set Temperature.
The display will return to the normal room temperature
after the keys have been released for 5 seconds.
Filter Monitor
The thermostat counts the number
of hours your system’s filter has been
in use. To maximize your system’s
performance and energy efficiency,
change or clean your filter regularly.
When the total system run time for heat and cool reaches
400 hours, the Filter Change Indicator will flash as a
reminder to check your system’s filter.
After changing or cleaning the system filter, press and
release the Filter Button. The usage hours will display on
the screen. Reset the display by pressing and holding the
Filter Button again until the hours displayed are zero (0).
Note: Pressing the Filter key at any time for less than 3
seconds will cause the Filter Change Indicator to appear
on the LCD. This is only to confirm key operation. The
counter is not affected unless the key is held for 3 seconds
or longer.
DIFF Setting
Your thermostat is set at the factory to cycle at 2°F (1°C)
above and below the set temperature (DIFF = 2). This
setting has been designed to provide a comfortable room
temperature under most conditions. However, if you find
your system cycling too fast or too slow, then the DIFF can
be adjusted to modify the cycle time.
• Press and hold BOTH up and down keys for three
seconds. DIFF will be displayed on the LCD.
• Press up to raise the DIFF to 3. This setting
INCREASES the time between cycles by
allowing your system to run LONGER.
• Press down to lower the DIFF to 1. This
setting DECREASES the time between cycles
by causing your system to run SHORTER.
The DIFF settings remain the same for both HEAT and
COOL, and can be changed in any System Switch position.
When batteries are installed in the thermostat, the DIFF is
reset back to setting 2.
Backlighting
Your thermostat has an electroluminescent lamp that
backlights the display for easy viewing in the dark. When
any key is pressed, the display is illuminated.
The display will remain illuminated for 7 seconds after the
last key is pressed. This allows the light to stay on if you
need to operate several keys.
Note: If the thermostat is in the Low Battery warning
condition, the backlight will not operate. Replace with 2
new AA alkaline batteries to restore the backlight function.
Low Battery Warning
Your thermostat has a two-stage low
battery warning system. When the
batteries are first detected to be weak,
the first stage low battery warning is
indicated by a battery symbol flashing
on the LCD display. Replace the batteries with 2 new
AA alkaline batteries. When the batteries become too
weak for normal operation, the thermostat enters the
second stage low battery warning which shuts down the
thermostat. In this condition, the battery symbol flashes
alone on the display and the thermostat will turn your
system off. Your system will remain off until the batteries
are replaced.
Note: The thermostat will still keep the current set
temperature and filter run time in memory until new
batteries are installed. After confirming that new batteries
have been inserted, the thermostat will return to normal
operation.
Error Mode
If the thermostat is unable to control
your system due to an unexpected
battery problem, the thermostat will
enter Error Mode. In this condition, the
thermostat flashes E1 or E2 on the LCD
display, and shuts off your system.
To correct this problem, replace the
batteries with 2 new AA alkaline
batteries, even if you have recently
replaced them. Next, remove the battery, hold any key,
then replace the battery again. You will need to reprogram
your thermostat and confirm normal operation. If Error
Mode returns, please call us for further information.
LCD Display Information
LCD Display
Information
E1
Sensor Error
E2
System Switch Error
Auto Cut Off
Your thermostat will automatically shut down in Heat
mode if the room temperature rises above 95°F (35°C).
It will shut down in cool mode if the room temperature
drops below 45°F (7°C).
Note that if your system has malfunctioned and no longer
responds to thermostat controls, the Auto Cut-Off will have
no effect.
Mechanical Heat Backup
This thermostat includes a bimetal switch that will
automatically turn on the Heat when the temperature
reaches about 41°F (5°C). WARNING: This switch only
activates the heating terminal (W). The system itself must
be capable of automatically turning the fan on. Without
normal fan operation, severe damage to the heating
system could result.
