Digital Thermostat

Digital Thermostat
OPERATION
Owners Manual
Start-up
Note: If the thermostat is in Low Battery warning condition, the backlight
will not operate. Replace with 2 new AA alkaline batteries to restore the
Backlight function.
The LCD will show the factory default display
Model:CT50
of 70˚F when batteries are first installed,.
TEMP
The temperature will update after a few
Low Battery Warning
seconds.
Your thermostat has a two-stage lower
battery
System Selector Switch
system
cool off heat
warning
system.
When
the
SET
TEMP
batteries are first detected to be weak, the
The System Selector switch on the front of the
first stage low battery warning is indicated
thermostat determines the operating mode of the
by battery symbol flashing on the LCD
thermostat. You may select COOL, OFF, HEAT.
display. At your earliest convenience, you
need to replace the batteries with 2 new AA alkaline batteries. When the
NOTE: Anytime you install or remove the thermostat from the wallplate,
batteries become too weak for normal operation, the thermostat enters the
Your new thermostat will provide years of reliable service. Using this
slide the System Selector to the OFF position to prevent the possibility of a
second stage low battery warning which shuts down the
digital thermostat will provide more uniform comfort in your home through
rapid system On – OFF.
this condition, battery symbol flashes alone on the display, and the
the seasons. Thank you for buying the product!
Fan Switch
Please read this manual for complete instructions on installing and
fan
thermostat. In
thermostat will turn your system off. Your system will remain shut-off until
the batteries are replaced.
The Fan switch should normally be located in the AUTO
Note: The thermostat will still keep the current Set Temperature and Filter
operating your thermostat. If you require further assistance, please feel
position. The Fan will be turned on along with normal
run time in memory until new batteries are installed. After confirming that
free to contact us.
operation of your system. In a normal gas or oil furnace,
new batteries have been inserted, the thermostat will return to normal
the Fan will be turned on by your furnace after its
operating .
on
IMPORTANT INFORMATION
auto
warm-up delay. For electric heat, air conditioning, and heat pump operation,
Error Mode
1. This thermostat is designed to work on the following systems:
the Fan will turn on with the system.
If the thermostat is unable to control your
 Gas – Standing Pilot
 Oil – Fired Furnace
To run the Fan on continuously, slide the Fan switch to the ON position.
 Gas – Electronic Ignition
 Single Stage Heat Pumps – with no
 Gas – Fired Boilers
auxiliary heat
system due to an unexpected battery
problem, the thermostat will enter Error
Review Current Set Temperature
Mode. In this condition, the thermostat
 Press either the up or down key once to see the Set Temperature.
flashes “E1”or “E2” on the LCD display, and
shuts off your system.
 Gas – Milivolt Systems
 Electric Furnace
The factory default is 68˚F when started with the System Switch Off or Heat,
 Oil – Fired Boilers
 Electric Air Conditioning
and 78˚F when started with the System Switch on Cool.
This thermostat will NOT control multistage heat pumps or 110/220V
baseboard electric heating systems.
2. Temperature Range
 Press either the up or down once and
This thermostat can be set between 45˚F and 95˚F. However, it will display
display the set temperature.
temperature is higher than 99˚F, and “LO” will be displayed if the
temperature is lower than 30˚F.
rises above 74˚F, and automatically cutoff in Cool mode if the temperature
drops below 74˚F.
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
service. However, when the batteries become drained 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
display will be cleared except for flashing Low Battery Indicator on the LCD
display.
have
recently
 Press either up or down again to change to
Mode returns, please call us for further
SET
TEMP
your desired Set Temperature. Hold the key
Set Temperature.
information.
Lcd display
information
Lcd display
information
E1
Sensor Error
E2
System switch Error
Auto Cut Off
Your thermostat will automatically cutoff in Heat mode if the room
The display will return to the normal room temperature after the keys have
temperature rises above 74˚F. It will cutoff in Cool mode if the room
been released for 5 seconds.
temperature drops below 74˚F.
Filter Monitor
Note that if your system has malfunctioned and no longer responds to
thermostat controls, the Auto Cut-Off will have no effect.
The thermostat counts the number of hours
INSTALLATION
your system’s filter has been in use. To
What You Need
maximize your system’s performance and
This thermostat includes two #8 slotted screws and two wall anchors for
energy efficiency, change or clean your filter
mounting. To install your thermostat, you should have the following tools
and materials.
 Slotted Screwdriver(s)
heat and cool reaches 400 hours, the Filter Change Indicator will flash as a
 Small Philips screwdriver
reminder to check your system’s filter.
 Hammer
After changing or cleaning the system filter, press and hold the Filter key
 Electric drill and 3/16” bit
for 3 seconds. The display will blink, and the counter will be reset to zero.
 Two 1.5V (AA) size alkaline batteries (included)
and keep the thermostat’s settings. Once the batteries have become too
low to ensure proper operation, your system will be turned off, and the
you
and confirm normal operation. If Error
regularly. When the total system run time for
Two fresh AA alkaline batteries should provide well about one year of
if
You will need to reprogram your thermostat
compressor restart due to short power outages.
4. Battery Warning
even
hold any key then place the battery again.
down for over 2 seconds to fast advance the
This thermostat will automatically cutoff in Heat mode if the temperature
batteries,
replaced them. Next, Move the battery out
Setting New Temperature
room temperatures from 30˚F to 99˚F. “HI” will be displayed if the
To correct this problem, replace the batteries with 2 new AA alkaline
Note: Pressing the Filter key at any time for less than 3 seconds will cause
Remove Old Thermostat
CAUTION: Do not remove any wiring from existing thermostat before
the Filter Change Indicator to appear on the LCD. This is only to confirm
reading the instructions carefully. Wires must be labeled prior to
key operation, and the counter is not affected unless the key is held for
removal.
greater than 3 seconds.
INPORTANT! Turn off the power to the furnace at the main power
CAUTION: When only the battery icon flashes on the display, the
panel or at the furnace.
thermostat is shut down, and your system will no longer operate. In this
SPAN Setting
condition, there is no temperature control of your dwelling.
Your thermostat is set at the factory to cycle at 2˚F above and below the set
have screws or other locking devices that must first be removed. Once the
NOTE: The backlight will not function when the thermostat is in low battery
temperature. (Span = 2) This setting has been designed to provide a
wall mounting plate is exposed, look for wires. If wires are not visible, they
condition.
comfortable room temperature under most all conditions. However, if you
may be connected to the back of the wallplate. Again, look for screws, tabs,
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
Remove existing thermostat cover and thermostat. Some thermostats will
find your system cycling too fast or too slow, then the Span can be adjusted
to modify the cycle time.
etc. Some models have doors that open to expose wires and mounting
screws. See Figure 1.
Typical Home Thermostats
 Press and hold BOTH up and down keys for three
prior to leaving.
seconds. SPAN will be displayed on the LCD.
5.Power supply
 Press up to raise the Span to 3. This setting
The thermostat shall be powered by 24 VAC and with batteries as backup.
INCREASES to cycle time by allowing your system
FEATURES
to run LONGER.
Structure of thermostat and explanation for the keypads
 Press down to lower the Span to 1. This setting
Wall mounting Plate
Thermostat
Cover
DECREASES the cycle time by causing your
Light: Backlight display automatically
with each key press for easy viewing.
Filter Key:
Resets the
filter change
counter to zero.
Filter Change
Indicator:Flashes
when filter needs
to be checked.
LCD Display:
Shows Room
Temperature,Set
Temperature,and
other feature
information as
required.
Up and Down Keys:
Keys for changing
the Temperature
setting. Also used
for adjusting the
Span.
FAN
SYSTEM
COOL
system to run SHORTER.
Low Battery Indicator. Flashes when
batteries need to be replaced.
OFF
HEAT
ON
AUTO
Fan Switch: Fan
switch for Automatic
or Continuous fan
operation.
System switch:
selector switch for
Heat,Cool,and Off.
Front Door:
Cover keys Open with one finger from left or right.
The Span 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 Span is reset back to
setting 2.
Wall mounting Plate
Thermostat
Cover
Figure 1
Backlighting
Wiring Labeling
Your thermostat has an electroluminescent lamp that backlights the display
 Each wire coming from the wall to the existing thermostat is connected to
for easy viewing in the dark.
a terminal point on that thermostat. Each of these terminal points is usually
When any key is pressed, the display is illuminated.
marked with a code latter as shown in Table A below.
 Note that this thermostat has multiple function terminals that allow
The display will remain illuminated for 7 seconds after the last key is
Single-Stage Heat Pump capability. Standard systems use: Rh, Rc, G, Y, W.
pressed. This allows the light to stay on if you need to operate several
[Single-Stage Heat Pumps use: R, Y, G, and O or B.] Table A below shows
keys.
the multiple functions of the terminals. Use the terminals that match your
system.
then leave the jumper wire between the Rh and Rc terminals on the
X-No Connection
 The number of wires in your system can be as few as two (for heat only
wallplate. Otherwise, if you have separate Rh and Rc wires (5-wire system),
Selector Switches
systems), as many as eight, or any number in between. If you follow the
then remove the jumper wire between the Rh and Rc terminals.
In order for this thermostat to control your system, the system type must be
specified by the selector switches on the printed circuit board inside the
labeling procedures correctly, you do not have to be concerned about how
many wires there are.
Connect Wires and Mount Thermostat to wallplate
 There is often no terminal marking on the existing thermostat of two wire,
 Match and connect the labeled wires to the appropriate coded terminal
heat only systems. Just connect either of the wires to the RH terminal, then
screws on the wallplate. (See Figure 4, 5.) Ignore any wires which may
connect the other wire to the W terminal to complete the circuit.
be present, but which were note connected to the old thermostat.
thermostat. There is also a selector switch for your choice of Fahrenheit or
Celsius temperature display. See figure 6.
 Heating System Selector (HG – HE switch)
The factory position for this switch is in the “HG” position. Leave it in this
position if you have a gas furnace or an oil burner. If you have an electric
 IMPORTANT! BEFORE DISCONNECTING ANY WIRES, APPLY THE
furnace, test to see whether the Heat and Fan come on as expected after
SELFADHESIVE LABELS PROVIDED TO THE WIRE AS SHOWN IN
installation. If the Fan operation is normal, leave it in the “HG” position. If
TABLE A BELOW. (For example, attach the label marked W to the wire that
the Fan does not come on within a minute of the thermostat calling for
toes to the W or H terminal on your existing thermostat.) IGNORE THE
heating, change the switch position to “HE”. The system selector has no
COLOR OF THE WIRES since these do not always comply with the
effect in the cooling mode.
standard.
NOTE: “HG” position is for gas and most other systems. “HE” position is for
 After labeling wires, disconnect them from the existing thermostat.
certain electric systems having a fan relay.
 System Selector (STANDARD – HEAT PUMP switch)
 Remove existing wallplate. To make sure wires do not fall back into wall
Rh
The factory position for this switch is in the STD position. Leave it in this
opening, you may want to tape them to the wall.
position if you have ANY system that uses gas, oil, electric, or hot water
 If hole in wall is larger than necessary for wires, seal this hole with
heating. If you have a single-stage Heat Pump (no auxiliary or emergency
insulating material so that no hot or cold air can enter the back of the
heat source), then slide the switch to the HP position. Be sure the reversing
thermostat from the wall. This air could cause a false thermostat reading.
Table A
valve wire is connected to the correct terminal for your heat pump (Rc/O) or
Figure 4
If the code letter on
then mark the wire
and connect to
your existing
with label shown
thermostat terminal
Thermostat is
shown
L
N
Figure 5
(Rh/B).
 Refer to the Wiring Diagrams below to be sure your system is wired
 ˚F / ˚C selector (Fahrenheit / Celsius)
correctly.
Your thermostat is set for ˚F mode from the factory. In order to change to ˚C
 If your system is a single stage heat pump and uses an O or B wire, you
mode, slide the switch to ˚C and hold any key about 2 seconds without the
must move the System Selector switch inside the thermostat to the Heat
battery, then place the battery again.
Pump position. If you have a normal furnace or electric system, leave the
NOTE: Unless press any key about 2 seconds without the battery, then
switch in the Standard position. Refer to the System Selector section on the
place the battery again.
back for more information on this switch.
 Be sure to tighten the terminal screws securely, otherwise a loose wire
could cause operational problems with your system or thermostat.
 Push excess wire back into the hole to prevent interference when
HG
installing the thermostat to the wallplate.
 Make sure the System Switch is set to OFF, and the Fan Switch is set to
HE
AUTO.
Insert the tabs on top of the thermostat body into the slots at the top of the
wallplate. Press the bottom of the thermostat body into the snap on the
bottom of the wallplate. Refer to Figure 2. (NOTE: Do not force the
thermostat onto the wallplate, as the terminal pins may be damaged. If it
does not snap properly, the thermostat may not work.)
Figure 6
 Insert the two AA size alkaline batteries, observing the polarity marked
inside the battery compartment.
 Switch on the main power at the panel or furnace.
TROUBLESHOOTING
Wiring Diagrams
Problem
Solution
No Display
1. Check battery connections and batteries.
NOTE: Do not connect a “Common” wire (sometimes
labeled “C”) to any terminal on this thermostat. Tape up the wire and do not
2. Move the battery out and wait for about 1
use. This wire provides electricity to non-battery powered thermostats.
minutes then Replace Batteries..
C
Entire
Mount wallplate and Thermostat
Display
1. Replace Batteries.
Dims.
 Remove the wallplate from your thermostat. See Figure 2.
Auto Fan Does Not
1. Move HG/HE selector to correct position.
Turn On Properly.
Heating or Cooling
Does Not Go On or
1. Check that the function switch is in the correct
position (“HEAT” or “COOL”).
C
Off.
2. There may be as much as 4-mintue delay
before the system turns On – wait and check.
(Compressor protection delay.)
3. Check your circuit breakers and switches to
ensure there is power to the system.
4. Replace batteries.
5. Make sure your furnace blower door is closed
C
properly.
6. If your non-heat pump system only uses
Figure 2
4-wires, be sure the jumper wire is installed
 Position wallplate on wall and pull existing wires through large opening.
between the Rh/B and Rc/O terminals.
Then level for appearance. Mark holes for plastic anchors provided, if
7. Check the position
your existing holes do not line up with those on the wallplate.
 Drill holes with 3/16” bit and gently tap anchors into the holes until flush
of the Reversing Valve
selector switch: Standard or Heat Pump.
C
8. If you have single-stage heat pump, be sure
with wall.
the jumper wire is installed between the Y and
 Reposition wallplate to wall, pulling wires through large opening. Insert
W terminals.
mounting screws provided into wall anchor and tighten. See Figure 3.
Erratic Display
1. Move the battery out hold any key then place
the battery again. Then reprogram.
If unit continues to
C
1. Replace unit.
operate in the Off
position.
Thermostat
1. Replace unit.
permanently reads
“HI”,
“LO”,
“E1” , “E2”.
C
Figure 3
NOTE: 5- Wire Systems
If your thermostat has one wire marked R or Rh (2, 3, or 4-wire system),
or