ComfortNET CTK02AA User manual

HiDef Communicating Control System
FEATURING SERIAL COMMUNICATIONS
INSTALLATION GUIDE
P/N CTK02AA

FAILURE TO READ AND FOLLOW ALL
INSTRUCTIONS CAREFULLY BEFORE
INSTALLING OR OPERATING THIS CONTROL
AND SYSTEM COULD CAUSE PERSONAL INJURY
AND/OR PROPERTY DAMAGE.
ATTENTION: MERCURY NOTICE
This product does not contain
mercury, but it may replace a
product that contains mercury.
Mercury and products containing
mercury must not be discarded
in household trash. Do not touch
any spilled mercury. Wearing non-
absorbent gloves, clean up any spilled
mercury and place it in a sealed
container. For proper disposal of a
product containing mercury or a sealed
container of spilled mercury, place
it in a suitable shipping container.
On the Internet, visit www.thermostat-
recycle.org for a location where the
product containing mercury can
be sent.
To prevent electrical shock and/
or equipment damage, disconnect
electric power to system at main fuse
or circuit breaker box until installation
is complete.
WARNING
Thermostat installation and all
components of the control system shall
conform to Class II circuits per the
NEC code.
WARNING
INTRODUCTION TO THERMOSTAT AND COMMUNICATING SYSTEM
This is the dealer installation and start-up instruction guide for the ComfortNet
HiDef Communicating Control System. It features a flexible programming
sequence for residential applications. It is designed to control components
of a 24 VAC residential ComfortNet communicating system featuring
ComfortNetTM protocol consisting of gas or electric heat, heat pump, and
central air conditioning applications. The high-resolution color display offers
easy readability, intuitive programming with individual touch buttons to the
right of the screen, on-screen prompting, pop-up message alerts to change
filter, or regular servicing check-ups, and an exchangeable faceplate. The
thermostat has a USB port for contractor setup.
The thermostat’s major features include 40o to 99oF setpoint range, 1o
resolution, 3.5-inch diagonal ¼ VGA LCD, auto configure, auto-changeover,
selectable continuous fan speeds, humidity control, dehumidification control,
dual fuel control, advanced diagnostics and fault code display, advanced
installer menu, simultaneous heat and cool program storage, a four-step
daily schedule sequence, energy management recovery, filter change-out
indicator, replace UV lamp indicator, change humidifier pad and program loss
start up temperature.
Note: If system power is lost for more than eight hours, the clock will have to
be reset. Programming and configuration settings will be saved.
!

Installation Guide / 1ComfortNet HiDef Control System
Installation........................................................................................................................... 2
Control Kits Content...................................................................................................... 2
Valid System Configurations......................................................................................... 2
Control Installation Location ......................................................................................... 3
Wiring Requirements .................................................................................................... 3
Installing Thermostat .................................................................................................... 5
Initial Power Up............................................................................................................. 6
Check System Operation.............................................................................................. 7
Thermostat Overview ......................................................................................................... 8
Thermostat Setup............................................................................................................... 9
Set Current Time and Day ............................................................................................ 9
Choose the System Setting .......................................................................................... 9
Energy Saving Factory Pre-Program ................................................................................ 10
Advanced Installer Menu ................................................................................................... 11
Communicating Control Operation................................................................................... 14
Equipment User Menus...................................................................................................... 15
Furnace User Menus .................................................................................................... 17
Air Handler User Menus ............................................................................................... 20
Heat Pump/Air Conditioner User Menus....................................................................... 22
Limited Warranty................................................................................................................. 25
Table of Contents Page

2 / Installation Guide ComfortNet HiDef Control System
This booklet contains installation instruction and information on the thermostat only. Separate installation
instructions for the furnace or air handler and outdoor AC condensing unit or heat pump are provided with the
appropriate equipment.This thermostat is designed exclusively for the ComfortNetTM communicating system.
Control Kits Content
This communicating control kit contains the following components:
■(1) Communicating control with base and silver faceplate
■(1) White snap on faceplate
■(2) 4-position plug color-coded connectors
■(2) Screws #6 x 3/4”long type A self tapping screws
Installation
■(2) Wall Anchors
■(1) Instruction Manual
■(1) Homeowner User Guide
■(1) Quick Start Guide
Valid System Configurations
This control may only be used with certain system configurations.Valid system configurations for
which this control can be used are:
■A communicating air handler matched with a communicating outdoor AC condensing unit.
■A communicating air handler matched with a communicating outdoor heat pump unit.
■A communicating furnace matched with a communicating outdoor AC condensing unit.
■A communicating furnace matched with a communicating outdoor heat pump unit.
■A communicating furnace matched with a non-communicating single-stage AC condensing unit.
System configurations other than those noted above will not function or
may function properly at greatly reduced performance.

ComfortNet HiDef Control System Installation Guide / 3
Wiring Requirements
Each digitally communicating device in the system requires four wire connections:
18 AWG solid wire is recommended.
24VAC Hot (R), 24VAC Common (C),Data 1 (1), and Data 2 (2).The R and C connec-
tions provide a 24VAC power supply that can be shared between the indoor and
outdoor units and the thermostat.The data 1 and data 2 connections provide the
communications bus between the indoor unit, outdoor unit and thermostat.Thus,
the R, C, 1, and 2 terminals must be wired consistently. See the indoor unit and
outdoor unit respective installation manuals for additional wiring details.
■Indoor unit to thermostat wiring: Connect a wire between terminal“R”on the
thermostat sub base and terminal“R” on the 4-position plug connector for the
indoor unit. Repeat for the C,1, and 2 terminals.
CTK02AA
Indoor
Board Terminal
Connections
Outdoor
Board Terminal
Connections
R
C
1
2
R
C
1
2
R
C
1
2
24VAC (Hot)
24VAC
(Common)
Data 1
Data 2
Control Installation Location
Locate the control on a vibration-free inside wall in an area having good air circulation.The control should be
located approximately five feet high.The control should be located in an area such that it is not influenced by
the following:
■Drafts
■Dead spots behind doors, in corners,
or under cabinets
■Cold or hot air from registers
■Sunlight
■Light from fixtures or other appliance
■Radiant heat from a fireplace or
other heat source
■Concealed water pipes (hot or cold)
■Unconditioned areas behind the control

4 / Installation Guide ComfortNet HiDef Control System
■Indoor unit to outdoor unit wiring: Connect a wire between terminal “R”on the indoor unit’s 4-position plug and
the terminal“R” on the outdoor unit’s 4-position plug connector. Repeat for the C, 1, and 2 terminals.
■Alternate indoor unit to outdoor unit wiring: In some installations, only two wires may be available for low voltage
control wiring at the outdoor unit.If this is the case, use the existing low voltage control wires and connect the 1 and
2 terminals as shown in the figure below. Follow instructions below to wire the system.
• Install the optional 40 VA transformer (Kit TFK01) in the outdoor unit using the screws provided. Align the holes in
the transformer mounting bracket with the holes in the sheet metal mounting panel and secure with screws.
• Connect one terminated end of the black 22”wire jumper to the 240VAC terminal on the transformer (or 208VAC
terminal if 208VAC system). Connect the othe terminated end of the wire jumper to L1 on the outdoor unit’s
control.
• Connect the red 22”wire jumper to the 240VAC COM terminal on the transformer. Connect the other end of the
wire jumper to L2 on the outdoor unit’s control.
• Connect the terminated end of the red 14”wire jumper to the 24VAC terminal on the transformer. Connect the
other end to the“R” terminal on the included plug connector.
• Connect the terminated end of the blue 14”wire jumper to the 24VAC COM terminal on the transformer. Connect
the other end to the“C” terminal on the included plug connector.
• Dual Fuel Systems: It is highly recommended that the optional 40VA transformer be used in the outdoor unit.See
alternate indoor unit to outdoor unit wiring for transformer wiring instructions.
• To maintain the UL rating on all AC and heat pump models the installing contractor is required to use the low
voltage wiring provided inside the control panel when converting to the communicating control system.
CTK02AA
Indoor
Board Terminal
Connections
Outdoor
Board Terminal
Connections
R
C
1
2
R
C
1
2
1
2
R
C
24VAC (Hot)
24VAC 230V
24VAC
(Common)
Data 1
Data 2
Optional Outdoor 40VA
Transformer (Kit TFK01)

ComfortNet HiDef Control System Installation Guide / 5
Installing Thermostat
■Carefully separate the thermostat body from the thermostat base.
■Place base at installation location and mark mounting hole locations on wall using base as a template.
■Drill mounting holes.
■Attach base snugly to wall using two mounting screws. Levelling is for appearance only and will not affect
thermostat operation.
■Connect wires to terminal block on base.
■18 AWG solid wire is recommended.
■Push excess wire into wall and plug hole with a fire resistant material (such as fiberglass insulation) to prevent drafts
from affecting thermostat operation.
■Carefully line up the thermostat with the base and snap into place.
Two Ways to Connect to the Outdoor Unit
METHOD ONE: 4-WIRE CONNECTION
Connect 4-Wire
Indoor Unit
Terminals 1 & 2 are communications wires.
They should never be connected to the 24 VAC
R&C power supply terminals.
Two Ways to Connect to the Outdoor Unit
METHOD TWO: 2-WIRE/TRANSFORMER CONNECTION
Low (24 VAC)
Voltage
High
Voltage
Transformer
Low Voltage
Connected to
R and C Terminals
Connect 2-Wires
to Indoor Unit
Connect High Voltage Transformer Leads to
L1 and L2 Male Spade Terminals on
Circuit Board.
Optional transformer
(P/N B1141643)
Install Thermostat on Interior Wall
NOTE: Thermostat
will automatically
configure to the
system once high
voltage power is
applied to the indoor
and outdoor equipment.
Remove and Inventory All
ComfortNet™ Components
Remove Outdoor Unit Cover
and 7-Pin Connector
P/N F0430675005
Install HVAC Components
Gas
Furnace
Air
Handler
Air Conditioner
or Heat Pump
Air Conditioner
or Heat Pump
Terminals 1 & 2 are
communications wires.
They should never be
connected to the 24 VAC
R&C power supply
terminals.
Remove 9-Pin Connector
from Furnace or
Air Handler Control
Connect 4-Wires
from Stat and 2 or
4 Wires from Outdoor Unit
P/N F0430679005
P/N F0430673005

6 / Installation Guide ComfortNet HiDef Control System
Removable Faceplate
The silver faceplate on the thermostat can be removed and
replaced with the white faceplate included. To change the
faceplate:
■Remove faceplate by gently pulling on the tabs behind the
lower edge of the faceplate. Lift faceplate off of thermostat.
■Position faceplate on top edge of thermostat.
■Press on bottom of faceplate to snap faceplate
back into position.
Tabs
Initial Power Up
Turn on AC power to the system.The thermostat will automatically
identify the communicating equipment installed and configure for
the equipment as required.
■Set the time (see thermostat setup section)
■Select advanced installer menu settings or use USB upload
feature to install Thermostat Configuration information
(see USB Upload section)
■Perform thermostat/system operation checkout.
■Program thermostat or accept factory programming.
■Touch to run schedule.

ComfortNet HiDef Control System Installation Guide / 7
Check System Operation
Heating System (Heat Pump only/Furnace only/Dual Fuel)
1. Press SYSTEM button until Heat is displayed.
2. Press to adjust thermostat setting 1° above room temperature.
The heating system should begin to operate.
3. If the heating system has additional stages, adjust the thermostat
setting to 3o F (2oC) or more above the actual temperature.The next
heat stage will energize.
4. Press to adjust thermostat setting below room temperature.
The heating system should stop operating.
Cooling System
1. Press SYSTEM button until COOL is displayed.
2. Press to adjust thermostat setting below room temperature.The cooling system should begin to operate.
3. If the cooling system has additional stages, adjust the temperature to 3oF (2o C) or more below the actual.The
second cool stage will energize within 10 seconds.
4. Press to adjust thermostat setting above room temperature.The cooling system should stop operating.
Fan Operation
1. Press FAN button until Fan On is displayed. The fan should begin to operate.
2. Press FAN button to change the display to Fan Auto.The fan should stop operating as long as there is no call for
heat or cool.

8 / Installation Guide ComfortNet HiDef Control System
Thermostat Overview
Navigating Through Your Thermostat Menus
Your thermostat features a simplified easy to understand menu structure.
■Press to enter the Main Menu
■Highlight a menu item using the or buttons
■Enter the item by pressing
■Use the or and the or to change menu items and settings
■Press the Home button to display the Home Screen.
■Press the Enter button to save any changes you have
made and display the previous menu item.
■If no button is pressed for two minutes, you will return to the home screen without saving changes.
Note: See Homeowner’s Guide for full details on thermostat menu options.
This manual only contains installation information.

ComfortNet HiDef Control System Installation Guide / 9
Thermostat Setup
Set the Current Time and Day
■On the Main Menu, select and enter Clock and
Display Settings.
■Select and Enter Time & Date.
■The Hour is selected. Adjust the hour with or .
■Press to select Minutes, AM/PM, Month, Day and
Year and adjust.
■The thermostat will automatically assign the correct
day of the week after the date is set.
■Press the Enter button.
Choose the System Setting
■From the Home screen, press the button as shown to
choose the system setting: Heat, EM, Cool, Auto, or Off.

10 / Installation Guide ComfortNet HiDef Control System
Energy Saving Factory Pre-Program
Your thermostat is programmed from the factory with the energy saving settings shown below for
every day of the week. If this program meets your needs, simply select either Heat, Cool, or Auto with the System button.
Factory Pre-Programmed Heating and Cooling Schedule
If you want to change the heating and/or cooling programs in your thermostat, see the “Programming
Your Thermostat” section in the Homeowner’s Guide.
Wake Up
(Morning)
Leave for Work
(Day)
Return Home
(Evening)
Go to Bed
(Night)
Heating Program 6:00 AM 70oF 8:00 AM 62oF 5:00 PM 70oF 10:00 PM 62oF
Cooling Program 6:00 AM 75oF 8:00 AM 83oF 5:00 PM 75oF 10:00 PM 78oF

ComfortNet HiDef Control System Installation Guide / 11
Advanced Installer Menu
This menu allows the installer to check installer-specific information or set advanced settings.It is accessible from the
Home screen when the and buttons are pressed at the same time for three seconds.
Select the items using the or buttons and press the button to enter the item to view information or change
settings. Press Enter button to save any changes and display the previous menu or press Home to display the Home
Screen. If 2 minutes pass without any buttons pressed, the Home Screen will return and changes will not be saved.
Items on the Advanced Installer Menu are:
■Communicating Devices
■Fault Status
■USB Upload
■Heat Pump Disable*
■Air Handler Lockout*
■Dual Fuel Setpoint:5°*
■Heat Cycle Rate:Medium
■Cool Cycle Rate: Medium
*Items marked with * may or may not appear in the list depending on the configuration of the system.
Communicating Devices: This menu item will list each piece of system equipment connected to the ComfortNetTM
network.The equipment can be selected and entered to view identifying information, operating information and setup
status as described in Equipment User Menus.
Fault Status: This menu item lists current equipment fault conditions.
The system equipment experiencing the fault will be listed with details of
the fault. If no faults are detected, this screen will show nothing.
USB Upload: The USB load menu displays a list of thermostat parameters that
can be loaded to the thermostat from a USB memory device. If the USB port
detects a USB memory device, this menu will automatically display.
Contractors can download the template at www.comfortnet1.com.
In the USB Upload menu, select the item to upload and press to
mark the item with a red box.After all items to upload are selected,
press the Upload button.

12 / Installation Guide ComfortNet HiDef Control System
The USB media must have properly formatted information to be recognized
by the thermostat. If the thermostat does not find information,when the
Upload button is pressed, the display will indicate, “Invalid Data Found.
Installation Failed!”
Once the Upload button is pressed and the upload is accomplished, the
display will indicate “Successfully Installed” for 3 seconds then the display
will display the menu or mode prior to entering the USB upload menu.
Air Handler Lockout Temperature: Available only for an air handler with
heat pump systems.This feature disables the electric heat above the selected
outdoor temperature.The temperature range is from the Heat Pump Disable
setting to 95oF. The default disable setpoint is 10° F.
Dual Fuel Setpoint: If the heating system is a heat pump with gas heat
and the outdoor sensor is installed,the thermostat can monitor outside
temperature to determine when to begin using the gas heat system and stop
the compressor.This temperature is the Dual Fuel temperature setpoint.The
Dual Fuel feature eliminates the need for a fossil fuel kit.
The display will indicate 30° (default).The temperature can be adjusted to
a value between 5° to 50°.The temperature will appear as °F unless °C is
selected for temperature display.
As long as the outside temperature is above the Dual Fuel Setpoint, the
compressor will operate.When the temperature drops below the setting the
thermostat will start the gas heat and shut off the compressor.
Heat Cycle Rate: Anticipation for heat cycle can be adjusted. Default setting
is Medium. If you wish to have longer heat cycles, change to Slow. For shorter
heat cycles change to Fast.

ComfortNet HiDef Control System Installation Guide / 13
Cool Cycle Rate: Anticipation for cool cycle can be adjusted. Default setting
is Medium. If you wish to have longer cool cycles, change to Slow. For
shorter cool cycles change to Fast.

14 / Installation Guide ComfortNet HiDef Control System
Communicating Control Operation
Multi-Stage Time Delay Operation
Your thermostat is designed to determine the optimum time to efficiently activate second stage operation.There is
a time delay algorithm from 0 - 30 minutes depending on the performance of the first stage and simply raising the
temperature in heating or lowering it in cooling will not always force a second stage demand.
EXAMPLE: For the last 2 hours the thermostat is set on 70° and the room temperature is 70° with the equipment using
only the first stage of heat. Since the equipment is keeping the temperature within 1° of set point, the thermostat will
delay second stage for a longer time if you manually raise the temperature or if the room temperature quickly changes.
Once the second stage is activated, the control will cycle second stage sooner the next time there is a difference
between the set point 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 first stage opera-
tion cannot achieve temperature in a reasonable time, the second stage will be activated sooner.This built in function
automatically optimizes the use of additional heating or cooling stages.
Dual Fuel Operation
This feature is for heat pump systems installed in conjunction with a gas furnace.
This control eliminates the need for an additional fossil fuel kit.
The dual fuel set point is adjustable in the Advanced Installer Menu (selectable from 5°F - 50°F – default 30°F) and
is based on feedback from the remote temperature sensor located in the outdoor unit.Above this setting and with
a first stage heating demand the heat pump will be engaged in heating mode.Below this setting or upon a second
stage heating demand the gas furnace will be engaged.Both first and second stage dual fuel operation staging will be
conducted as is outlined in the Multi-Stage Time Delay Operation section above.

ComfortNet HiDef Control System Installation Guide / 15
Additional equipment operating information and options will be found on the Advanced Installer Menu in
Communicating Devices. Equipment fault status and details will be found in Fault Status. Push and hold the
right and left button to enter this menu.
In the Communicating Devices menu, select the equipment listed that you wish to see information for.The display will
indicate “Accessing the Device”. The list of parameters for the equipment will appear. Select the parameter you wish
to view.
Each Equipment User Menu has submenus to divide the information into categories. Each piece of equipment has
a different set of submenus, with different parameters depending on the equipment.The submenus show similar
information for each piece of equipment.
The equipment found in the system will be displayed.
Touch or to step through the list of equipment connected, including thermostat.
To view the Equipment Menus information for the equipment displayed select the desired menu to enter that
equipment submenu.The message area will show “ACCESSING THE DEVICE” to indicate that the thermostat is
retrieving data.Then the first equipment submenu name will appear.
Touch or to step through the list of equipment submenus. Each piece of equipment may have different
submenus.
When the equipment submenu you want is showing, touch the button.The display will show “ACCESSING THE
DEVICE” and then change to the first parameter on the equipment submenu.Settings for the parameter will also
appear on the display.
Touch or to step through the items of the equipment submenu and view settings.
If a setting can be adjusted, the options will appear.Change the setting as required.Touch or to step to the next
item. “UPDATING THE SUBSYSTEM” will appear and then the display will show “DONE”to indicate the change is
accepted.
Equipment User Menus

16 / Installation Guide ComfortNet HiDef Control System
Touch HOME to step out of the equipment submenu and back to the main menu.Touch Enter to step back one
menu level.
Each Equipment User Menu has submenus to divide the information into categories. Each piece of equipment
has a different set of submenus, with different parameters depending on the equipment. The submenus are
showing the similar information for each piece of equipment. The submenus and the information they
provide are:
Configuration: This submenu item provides access to information regarding the configuration of the
particular piece of equipment. An example of configuration data is the number of cooling stages for an AC
condensing unit.
■Diagnostics: This submenu item provides access to the fault history for the particular piece of equipment. It
also provides a means to clear the fault history.
■Identification: This submenu item provides access to the model number and serial number for the particular
piece of equipment.
■Sensors: This submenu item provides access to available sensor data for the particular piece of equipment.
In some instances, it may also provide a means to enable or disable a particular sensor.
■Setup: This submenu item provides access to modifiable operational parameters for the particular piece of
equipment.
■Status: This submenu item provides access to the current status of a particular piece of equipment.
The following sections provide detailed listings of the available submenus for the various types of equipment that
may be used with this digitally communicating thermostat. The submenu listing is further broken down into the
various submenu items. Note: Some menus may not be displayed depending on the configuration.

ComfortNet HiDef Control System Installation Guide / 17
Furnace User Menus
Configuration (CONFIG)
Sub-menu Item Indication (for Display Only; not User Modifiable)
Number of Heat
Stages (HT STG)
Displays the number of furnace heating stages
Input Rate (BTU/HR) Displays the furnace input rate in kBtu/hr
Motor HP (1/2, 3/4
or 1 MTR HP)
Displays the furnace indoor blower motor horse power
Diagnostics (DIAG)
Sub-menu Item Indication/User
Modifiable Options
Comments
Fault 1 (FAULT #1) Most recent furnace fault For display only
Fault 2 (FAULT #2) Next most recent furnace fault For display only
Fault 3 (FAULT #3) Next most recent furnace fault For display only
Fault 4 (FAULT #4) Next most recent furnace fault For display only
Fault 5 (FAULT #5) Next most recent furnace fault For display only
Fault 6 (FAULT #6) Least recent furnace fault For display only
Clear Fault History
(CLEAR)
NO or YES Selecting “YES” clears the fault history
NOTE: Consecutively repeated faults are shown a maximum of 3 times.

18 / Installation Guide ComfortNet HiDef Control System
Identification (IDENT)
Sub-menu Item Indication (for Display Only; not User Modifiable)
Model Number
(MOD NUM)
Displays the furnace model number
Serial Number
(SER NUM)
Displays the furnace serial number (Optional)
Software
(SOFTWARE)
Displays application software revision
Setup (SETUP)
Sub-menu Item User Modifiable Options Comments
Heat Airflow Trim
(HT TRM)
-10% to +10% in 2% Increments
(Default 0%)
Trims the heating airflow by the selected
amount.
Heat ON Delay
(HT ON)
5, 10, 15, 20, 25, or 30 seconds
(Default 20)
Selects the indoor blower heat on delay
Heat OFF Delay
(HT OFF)
30, 60, 90, 120, 150, or 180
seconds (Default 120)
Selects the indoor blower heat off delay
Heating Air Flow
(HT ADJ)
1, 2, 3, 4 (Default 2) Selects the nominal heating airflow