Venstar T1900 User manual

Venstar Inc. 08/07
Use with most Air Conditioning & Heating Systems including: 1 or 2 Stage
Electric Cooling & 3 Stage Gas Heating, Heat Pump, Electric or Hydronic Heat.
Digital
Thermostat
Digital
Thermostat
residential
T1
900
HEAT
COOL HEAT
PUMP
PROGRAMMABLE
7-DAY
PROGRAMMABLE
7-DAY
up to
& 2-cool
up to
& 2-cool
3-heat
3-heat
THERMOSTAT
with HUMIDITY
CONTROL
Control up to 3 Heat &
2 Cool Stages
3 Configurable Outputs
Timers & Deadbands
Backlit Display & Button
Legends
Aux Heat Indicator
Adjustable 2nd & 3rd Stage
Dry Contact Equipped
Outdoor Sensor Ready with
High/Low Readouts for the Day
Equipped with Optional Humidity
Module: Controls Humidification,
Dehumidification and Reheat
Programmable Output
Accepts EZ Programmer
Accepts Optional IR Remote Control
Accepts Comfort Call
Phone Control Accessory
INSTALLATION
INSTRUCTIONS
INSTALLATION
INSTRUCTIONS

Page i
NOTE: Due to variations in environmental conditions, it is not
always possible to achieve the desired humidification or
dehumidification setpoint.
MISC3 MISC3
OK
This device complies with Part 15 of the FCC Rules. Operation is
subject to the following two conditions: (1) this device may not cause
harmful interference, and (2) this device must accept any interference
received, including interference that may cause undesired operation.
Follow the Installation Instructions before proceeding.
Set the thermostat mode to “OFF” prior to changing
settings in setup or restoring Factory Defaults.
NEVER PUT MORE THAN ONE
JUMPER ON THE SAME MISC
JUMPER BLOCK!
THIS MAY DAMAGE YOUR
THERMOSTAT AND VOID
YOUR WARRANTY.
CAUTION
4Z95
CAUTION
C
c
F
FOR HOME OR OFFICE USE
Tested to Comply
with FCC Standards
Thermostat T1900

8
2
1
3
6
7
4
5
Preparation
Remove & Replace the
Old Thermostat
Configuring the MISC
Outputs
Wiring Diagrams
Calibrating the
Thermostat Sensors
Test Operation
TroubleShooting
Page iii
Table of Contents
Wire Connections

Page 1.1
SECTION 1
Preparation
1
Assemble tools
Flat Blade
Screwdriver
Wire cutter
& Stripper
Make sure your Heater/Air Conditioner is working
properly before beginning installation of the
thermostat.
Carefully unpack the thermostat. Save the screws,
bracket, and instructions.
Turn off the power to the Heating/Air Conditioning
system at the main fuse panel. Most residential
systems have a separate breaker for disconnecting
power to the furnace.
Proper installation of the thermostat will be
accomplished by following these step by step
instructions. If you are unsure about any of these
steps, call a qualified technician for assistance.
AUTO
I2:00
Pm
HEAT
COOL
72
74
AUTO
I2:00
Pm
HEAT
COOL
72
74
AUTO
I2:00
Pm
HEAT
COOL
72
74
AUTO
I2:00
Pm
HEAT
COOL
72
74
AUTO
I2:00
Pm
HEAT
COOL
72
74

Page 2.1
SECTION 2
Remove & Replace the Old Thermostat
2
Remove the cover of the old thermostat.
If it does not come off easily check for screws.
Loosen the screws holding the thermostat
base or subbase to the wall, and lift away.
Disconnect the wires from the old thermostat.
Tape the ends of the wires as you disconnect
them, and mark them with the letter of the
terminal for easy reconnection to the new
thermostat.
Keep the old thermostat for reference purposes,
until your new thermostat is functioning properly.
AUTO
I2:00
Pm
HEAT
COOL
72
74
AUTO
I2:00
Pm
HEAT
COOL
72
74
AUTO
I2:00
Pm
HEAT
COOL
72
74
AUTO
I2:00
Pm
HEAT
COOL
72
74

3
Page 3.1
Section 3 Contents:
Configuring the Jumpers........3.2
Explanation of Jumper
Settings..................................3.3
SECTION 3
Configuring the MISC Outputs

3
Page 3.2
Configuring the Jumpers
NEVER PUT MORE THAN
ONE JUMPER ON THE SAME
MISC JUMPER BLOCK!
DOING SO MAY DAMAGE
YOUR THERMOSTAT AND
VOID THE WARRANTY.
MISC3 MISC3
OK
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
CAUTION
For additional flexibility, your thermostat has three configurable
outputs. These outputs are designed to have different functions
depending on how the jumpers are set (below).
Each output, labeled MISC1, MISC2, and MISC3 may be set for one
of the five choices available.
In the diagram below, the MISC3 jumper has been set for HUM
(humidification) operation, the MISC2 jumper has been set for DEHUM
(dehumidification) operation, and the MISC1 jumper has been set for
PROG (programmable) operation.
HP
GAS
B
O
ELEC
GAS
(FAN)
W1
Y1
G
R
C
MISC2
CK1
CKGND
W2
MISC1
RS2
RSGND
MISC3
RS+5
Rs1
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
INSTALL HUMIDITY
MODULE WITH SENSING
ELEMENT OUTWARD
HUM NO HUM
1
2
4
6
8
X
Z
1
5
7
9
Y
3

Page 3.3
W3 JUMPER SETTING
If the jumper for MISC1, MISC2, or MISC3 is set to W3, the corresponding MISC
screw terminal on the backplate will control a third stage of heat.
3
PROG JUMPER SETTING
If the jumper for MISC1, MISC2, or MISC3 is set to PROG,
terminal on the backplate will control a pilot relay or other accessory.
the corresponding MISC screw
The 3rd Stage of Heat is turned on when:
(A) The 1st and 2nd stages have been on for the time required (steps 27
and 28, page 14.6). It is adjustable from 0-60 minutes and the default
is two minutes.
(B) The temperature from the setpoint is equal to or greater than: the set-
point plus the 1st stage deadband (step #24, 14.5), plus the 2nd stage
deadband (step #25, 14.5) plus the 3rd stage deadband (step #26,
14.5). This 3rd stage deadband is adjustable from 0-10 degrees and
the default is two degrees.
Explanation of Jumper Settings
And
Heat
Setpoint
Cool
Setpoint
Deadband Deadband DeadbandDeadbandDeadband
db 1 db 1db 2 db 2db 3 (adj. 1-6 )(adj. 0-10 )(adj. 0-10 ) (adj. 0-10 )(adj. 1-6 )
1st Stage
turn on
2nd Stage
turn on
3rd Stage
turn on
1st Stage
turn on
2nd Stage
turn on
Heating
Cooling
TEMPERATURE
DECREASE INCREASE
W3 MULTI-STAGE OPERATION EXPLAINED - SECTION 14 of the Owner’s
Manual
This jumper setting allows the MISC outputs to control a pilot relay by time,
temperature, or a signal from the Internet/Phone. The following are three
possible scenarios:
By Time: A device that requires a start and stop time. An example
of this would be an exterior lighting system that needed to be
energized every day between the hours of 8pm and 1am.
By Temperature: An exhaust fan that needs to energize whenever
the temperature from RS2 rises above 90 degrees F.
By Remote: Remotely arming a security system through the web or phone.
PROGRAMMABLE OUTPUT - SECTION 15 of the Owner’s Manual

DEHUM JUMPER SETTING
HUM JUMPER SETTING
If the jumper for MISC1, MISC2, or MISC3 is set to HUM,
terminal on the backplate will control a humidification system.
the corresponding MISC screw
Explanation of Jumper Settings (continued)
If the jumper for MISC1, MISC2, or MISC3 is set to DEHUM,
terminal on the backplate will be connected to the dehumidification terminal of a furnace board.
NOTE: Not all furnaces have a dehumidification terminal.
the corresponding MISC screw
DEHUMIDIFICATION OPERATION - SECTION 10 of the Owner’s Manual
If your HVAC unit is equipped with a dehumidification system the thermostat will
operate in one of two ways.
1) Normally Closed (NC): The thermostat will de-energize the MISC1, MISC2,
or MISC3 terminal of the thermostat (this MISC terminal is connected to the
DEHUM terminal on your furnace) to allow the fan to run in low speed when
the humidity in the home is above the dehumidify setpoint you have chosen
and there is a call for 1st stage cooling.
2) Normally Open (NO): The thermostat will energize the MISC1, MISC2, or
MISC3 terminal of the thermostat (this MISC terminal is connected to the
DEHUM terminal on your furnace) to allow the fan to run in low speed when
the humidity in the home is above the dehumidify setpoint you have chosen
and there is a call for 1st stage cooling.
HUMIDIFICATION OPERATION - SECTION 9 of the Owner’s Manual
If your HVAC unit is equipped with a humidification system the thermostat will
provide power to the MISC1, MISC2, or MISC3 terminal of the thermostat when
the humidity in the home falls below the humidity setpoint you have chosen.
The value for this setpoint ranges from 0% to 60%. If no humidity is desired
or if a humidification system has not been installed, set the value to OFF.
Page 3.4
3

Page 3.5
3Y2 JUMPER SETTING
If the jumper for MISC1 is set to Y2 the
will control a second stage of cooling.
MISC1 screw terminal on the backplate
Y2 OPERATION - SECTION 14 of the Owner’s Manual
Control up to two Cool stages.
The 2nd Stage of heat or cool is turned on when:
(A) The 1st Stage has been on for the time required (step #27,
page 14.6). It is adjustable from 0-60 minutes and the default
is two minutes.
(B) The temperature spread from the setpoint is equal to or greater
than: the setpoint plus the deadband (step #24, page 14.5), plus
the 2nd deadband (step #25, page 14.5). This 2nd deadband is
adjustable from 0-10 degrees and the default is two degrees.
Explanation of Jumper Settings (continued)
And
Cool
Setpoint
DeadbandDeadband
db 1 db 2
(adj. 0-10 )(adj. 1-6 )
1st Stage
turn on
2nd Stage
turn on
Cooling
TEMPERATURE INCREASE

Page 4.1
SECTION 4
Wire Connections
4
If the terminal designations on your old thermostat
do not match those on the new thermostat, refer
to the chart below, or the wiring diagrams
that follow.
* O/B is used if your system is a Heat Pump.
** For instructions on connecting these terminals see page 16.2
of the Owner’s Manual.
Wire from the
old thermostat
terminal marked Function
Install on the
new thermostat
connector marked
G or F Fan G
Y1, Y or C Cooling Y1
W1, W or H Heating W1/O/B
PowerRh, R, M, Vr, A R
C
O/B
C
Common
Rev. Valve
W2 2nd Stage Heat
RS+5 Remote Sensor +5vdc
Remote Sensor Signal
CKGND Dry Contact Switch 2
RS+5**
RS1**RS1
RSGND Remote Sensor Ground RSGND**
CK1 Dry Contact Switch 1 CK1
CKGND
W1/O/B*
W2
MISC1
MISC2
MISC3
MISC1
MISC2
MISC3
RS2 RS2**
Remote Sensor Signal #2
Configurable Output #1
Configurable Output #2
Configurable Output #3
AUTO
I2:00
Pm
HEAT
COOL
72
74

Page 5.1
Section 5 Contents:
HVAC Equipment Wiring............5.2
MISC1, MISC2, and MISC3
Wiring........................................5.6
Remote Sensor, Outdoor Sensor
and CK1-CK2 wiring for the
Time Clock................................5.8
SECTION 5
Sample Wiring Diagrams
5

Y1
G
R
C
MISC2
CK1
CKGND
W1/O/B
MISC1
RS+5
RS1
RSGND
W2
6 Conductor 18 gauge
unshielded cable from the
thermostat to the equipment.
24 vac return
fan relay
compressor relay
1st stage heat circuit
W1
W2 GRC
Y1
RS2
6 Wire, 1 Stage Cooling, 1 Stage Heat
24 vac common
2nd stage heat circuit
MISC3
HP
GAS
B
O
ELEC
GAS
(FAN)
W1
Y1
G
R
C
MISC2
CK1
CKGND
W2
MISC1
RS2
RSGND
MISC3
RS+5
Rs1
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
INSTALLHUMIDITY
MODULEWITH SENSING
ELEMENTOUTWARD
1
2
4
6
8
X
Z
1
5
7
9
Y
3
HUM NOHUM
HP
GAS
B
O
ELEC
GAS
(FAN)
Residential & Commercial 1 Stage Cooling,
with 1st stage Gas Heat
Commercial Heat Pump 1 Stage Cooling
with 2 Stage Heat
OR
Page 5.2
5

Y1
G
R
C
MISC2
CK1
CKGND
W1/O/B
MISC1
RS+5
RS1
RSGND
W2
6 Conductor 18 gauge
unshielded cable from the
thermostat to the equipment.
24 vac return
fan relay
compressor relay
1st stage heat circuit
W1
W2 GR C
Y1
RS2
Residential & Commercial 1 Stage Cooling,
with 1st stage Electric Heat
6 Wire, 1 Stage Cooling, 1 Stage Heat
24 vac common
2nd stage heat circuit
MISC3
HP
GAS
B
O
ELEC
GAS
(FAN)
Page 5.3
5
HP
GAS
B
O
ELEC
GAS
(FAN)
W1
Y1
G
R
C
MISC2
CK1
CKGND
W2
MISC1
RS2
RSGND
MISC3
RS+5
Rs1
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
INSTALLHUMIDITY
MODULEWITH SENSING
ELEMENTOUTWARD
1
2
4
6
8
X
Z
1
5
7
9
Y
3
HUM NOHUM

Y1
G
R
C
MISC2
CK1
CKGND
W1/O/B
MISC1
RS+5
RS1
RSGND
W2
6 Conductor 18 gauge
unshielded cable from the
thermostat to the equipment.
24 vac return
Fan Relay
Compressor Relay
Reversing Valve
O
W2 GR C
Y1
RS2
Residential Heat Pump with O Reversing
Valve 1 Stage Cooling, with 2 stage Heat
6 Wire, 1 Stage Cooling, 2 Stage Heat
24 vac common
2nd stage heat circuit
MISC3
HP
GAS
B
O
ELEC
GAS
(FAN)
Page 5.4
5
HP
GAS
B
O
ELEC
GAS
(FAN)
W1
Y1
G
R
C
MISC2
CK1
CKGND
W2
MISC1
RS2
RSGND
MISC3
RS+5
Rs1
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
INSTALLHUMIDITY
MODULEWITH SENSING
ELEMENTOUTWARD
1
2
4
6
8
X
Z
1
5
7
9
Y
3
HUM NOHUM

Y1
G
R
C
MISC2
CK1
CKGND
W1/O/B
MISC1
RS+5
RS1
RSGND
W2
6 Conductor 18 gauge
unshielded cable from the
thermostat to the equipment.
24 vac return
W2 GR C
Y1
RS2
Residential Heat Pump with b Reversing
Valve 1 Stage Cooling, with 2 stage Heat
6 Wire, 1 Stage Cooling, 2 Stage Heat
24 vac common
2nd stage heat circuit
MISC3
HP
GAS
B
O
ELEC
GAS
(FAN)
Fan Relay
Compressor Relay
Reversing Valve
Page 5.5
5
b
HP
GAS
B
O
ELEC
GAS
(FAN)
W1
Y1
G
R
C
MISC2
CK1
CKGND
W2
MISC1
RS2
RSGND
MISC3
RS+5
Rs1
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
INSTALLHUMIDITY
MODULEWITH SENSING
ELEMENTOUTWARD
1
2
4
6
8
X
Z
1
5
7
9
Y
3
HUM NOHUM

HP
GAS
B
O
ELEC
GAS
(FAN)
W1
Y1
G
R
C
MISC2
CK1
CKGND
W2
MISC1
RS2
RSGND
MISC3
RS+5
Rs1
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
INSTALLHUMIDITY
MODULEWITH SENSING
ELEMENTOUTWARD
1
2
4
6
8
X
Z
1
5
7
9
Y
3
HUM NOHUM
Y1
G
R
C
MISC2
CK1
CKGND
W1/O/B
MISC1
RS+5
RS1
RSGND
W2
2nd Stage Cooling
Y2 W3
RS2
3rd Stage Heat
or Dual Fuel
MISC3
Sprinkler System
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
Page 5.6
5
Adding a (MISC1), Sprinkler System (MISC2),
and 3rd Stage of Heating or Dual Fuel Applications (MISC3)
2nd Stage of Cooling

HP
GAS
B
O
ELEC
GAS
(FAN)
W1
Y1
G
R
C
MISC2
CK1
CKGND
W2
MISC1
RS2
RSGND
MISC3
RS+5
Rs1
W3
PROG
HUM
DEHUM
MISC3 MISC2 MISC1
Y2
(MISC1
ONLY)
INSTALLHUMIDITY
MODULEWITH SENSING
ELEMENTOUTWARD
1
2
4
6
8
X
Z
1
5
7
9
Y
3
HUM NOHUM
Y1
G
R
C
MISC2
CK1
CKGND
W1/O/B
MISC1
RS+5
RS1
RSGND
W2
RS2
Adding a Humidification System (MISC1) and Dehumidification System (MISC2)
MISC3
Dehumidification
System
Humidification
System
HUM
NO HUM
Page 5.7
5
W3
PROG
HUM
DEHUM
MISC3 MISC2
Y2
(MISC1
ONLY)
MISC1

CK1 and CK2 terminals wired to a Time Clock
DRY CONTACT SWITCH - The terminals are ‘normally open’ (or may be programmed for
normally closed operation, see page 17.2 of the Owner’s Manual). Closing or
completing the circuit will cause the thermostat to do one of the following:
1) If Vacation is selected in step #41 of the Advanced Setup (see page 17.3 of the
Owner’s Manual), when the dry contact is energized the thermostat will be forced into
Vacation mode (see Section 20 of the Owner’s Manual).
2) If Service Pan is selected, when the dry contact is energized the thermostat will lockout
Y1 (compressor) and write Service Pan on the display.
Page 5.8
5
Y1
G
R
C
MISC2
CK1
CKGND
W1/O/B
MISC1
RS+5
RS1
RSGND
W2
RS2
MISC3
12
11
10
9
8
765
4
3
2
1
For instructions on wiring the optional Remote and Outdoor
Sensors, please see page 16.2 of the Owner’s Manual