Venstar T1075 Programmable Thermostat
Front Panel
- Liquid Crystal Display
- Up/Down Buttons
- Mode Button
- Fan/Override Button
- Heat or Cool Indicator
Heat = Red, Cool = Green
Display
- Mode Indicators – Pages 7-10
Selects the operational mode of the equipment.- HEAT – Indicates the heating mode.
- COOL – Indicates the cooling mode.
- AUTO – Indicates the system will automatically changeover between heat and cool modes as the temperature varies.
- PROGRAM ON – Indicates the time period program is enabled to run.
- OFF – Indicates heating and cooling are turned off.
- Clock with Day of the Week – Page 6
Indicates the current time and day. This clock is also used to program the time period schedules. - Room Temperature Display
Indicates current room temperature. - Desired Set Temperature – Page 11
Indicates desired room temperature(s).
- Override icon – Pages 12 & 22
Indicates the program is currently being overridden for up to six hours. - Occupied & Unoccupied icons – Pages 13-16
Indicates the program number: Occupied 1,2,3 or Unoccupied. - Setup icon – Pages 18-23
Indicates the thermostat is in the advanced setup mode. - Fan icon
– Page 11
Indicates fan operation.
Fan
= low speed
Fan
= medium speed
Fan= high speed
When only the Fan icon is displayed, the fan is in the Auto mode and will run only when necessary to heat or cool.
- Start & Stop icons – Pages 14-16
Appear when programming occupied time periods. - Locked icon – Page 31
Indicates keypad has been locked. - Outside icon – Page 32
Indicates the temperature displayed is from the optional outside sensor.
Quick Start Set the Clock and Go
Press the MODE and FAN buttons at the same time for two seconds to enter Setup screens.
The thermostat is preprogrammed from the factory to operate a 4 pipe system without the need for further programming. To optimize the installation of this thermostat for a 2 pipe system, follow the instructions in the Advanced Setup section.
Selecting the Heat or Cool Mode 4-Pipe Operation
Select Mode by Pressing the MODE Button
Selecting the Heat or Cool Mode 2-Pipe Operation
Heating and/or Cooling
Step #6 = 3 in Advanced Setup (page 19), and the accessory changeover sensor (ACC-SENFC) is used.
Step #6 = 4 or 5 in Advanced Setup (page 19). Operation is the same as a 4-pipe system .
Basic Operation
Selecting Your Desired Temperature (adjusting the setpoints)
AUTO OR PROGRAM MODE
Pressing the UP or DOWN button when both Heat & Cool setpoints are visable will adjust both the heat and cool set temperatures simultaneously.
Overriding the Daily Schedule
Pressing and holding the FAN button for 5 seconds may be used to interrupt the normal time schedule programming of the thermostat. The override feature may only be used when the thermostat is running the time schedule, in Program On mode.
- Unoccupied Operation – During programmed, unoccupied periods pressing and holding the FAN button for 5 seconds will temporarily force the thermostat into Occupied 1 comfort settings for one to six hours (step #14, page 22). The Override icon will be illuminated during this time. If you press and hold the FAN button while the thermostat is currently overriding the daily schedule, this will reset the timer, returning the thermostat to the correct time period program for the day.
- Occupied Operation – Pressing and holding the FAN button for 5 seconds during a programmed Occupied time period will have no effect.
Programming Occupied & Unoccupied Periods
Press the MODE button. While holding MODE, press the UP button for two seconds to enter time period programming.
The copy command becomes available after the maximum # of occupied periods are programmed in a day. This example uses 1 as the maximum occupied periods ever programmed in one day.
PROGRAMMING NOTES
- You will be prompted to enter both heat and cool setpoints even if the thermostat is configured for heat only, or cool only.
- If only 1 Occupied period is selected, the Occupied 2 & 3 steps will be skipped. Further, if only 2 occupieds are selected, the Occupied 3 steps will be skipped.
- Heat & Cool setpoints for Occupied 1 are the same for each day. Heat & Cool setpoints for Occupied 2 & 3 can be adjusted differently for each day, if desired.
- If the start time is set for later than the stop time, the program will run from the start time to midnight and from midnight to the stop time on the same day. For example: 9:00pm start, 8:00am stop, on Monday. This program will run from 12:00am Monday to 8:00am and again from 9:00pm to 11:59pm on Monday.
- The Unoccupied settings take effect at all times when: (1) the program is on and (2) the current time is outside an occupied period. For this reason start and stop times are not necessary for unoccupied.
- If the same start and stop times are programmed in for an occupied period, then it will run 24 hours.
- If one occupied period starts and stops within another occupied period, the lower occupied # has priority. example: If Occupied 3 is programmed to be “on” 24 hours, and Occupied 2 is programmed to run that day, then Occupied 2 settings will take precedence during that time.
- During the Override mode (see page 12), the Occupied 1 Heat & Cool setpoints are used.
Advanced Setup
| Step Description Range Default | ||
| 1 Time of Day | 24 Hour | 12:00am |
| 2 Day of Week | Mo – Su | Mo |
| 3 Display Blanking | On / Off | On |
| 4 Single or Dual Setpoint | 1 /2 | 2 |
| 5 2 or 4 Pipe System | 2 / 4 | 2 |
| 6 2 Pipe System Operation | 1 – 5 | 1 |
| 7 Fan Auto Operation | On / Off | Off |
| 8 Fan Coil Type | On – Off | Off |
| 9 1st Stage Deadband | 1 – 6 | 2 |
| 10 Minimum Heat/Cool | 0 – 6 | 2 |
| 11 Backlight | On / Off | Off |
| 12 Degrees F or C | F / C | F |
| 13 Sensor Operation | On / Off | Off |
| 14 Override Timer Length | 0 – 6 Hours | 2 Hours |
| 15 Dry Contact Polarity | Occ. / Unocc. | NO /NC |
| 16 Dry Contact Operation | Unocc. / Occ. | Occ. |
| 17 Dry Contact Operation | Unocc. / Off | Unocc. |
About Advanced Features & Operation
CALIBRATION – Under normal circumstances it will not be necessary to adjust the calibration of the temperature sensor. If calibration is required, please contact a trained HVAC technician to correctly perform the following procedure.
DEADBAND OPERATION – Controls one Heat and one Cool stage with a three-speed fan (see below).
- The low-speed fan for heat or cooling is turned on when:
The temperature spread from the setpoint is equal to or greater than the setpoint plus the 1st stage deadband (step #9, page 20). This 1st stage deadband is adjustable from 1-6 degrees and the default is two degrees. - The medium-speed fan for heat or cooling is turned on when:
The temperature spread from the setpoint is equal to or greater than the setpoint plus the 1st stage deadband (step #9, page 20), plus the 2nd stage deadband. This 2nd stage deadband is fixed at one degree and is not adjustable. - The high-speed fan for heat or cooling is turned on when:
The temperature spread from the setpoint is equal to or greater than the setpoint plus the 1st stage deadband (step #8, page 20), plus the 2nd stage deadband, plus the 3rd stage deadband. This 3rd stage deadband is fixed at one degree and is not adjustable.
The above figure assumes the minimum on time for the prior stage has been met to allow the next stage to turn on, once the deadbands have been exceeded.
DRY CONTACT SWITCH –
This feature allows an external device such as a Central Time Clock, Occupancy Sensor, or a Telephone activated device to force one or more thermostats into an Occupied or Unoccupied mode (steps #15 and 16, page 22).
When the CK1 and R terminals are shorted together, and the thermostat is programmed for Unoccupied operation (step #16, page 22), the thermostat will be forced into Unoccupied setpoints or Off (step#17, page 23) and the Unoccupied icon will appear on the display.
Note: The thermostat must be in Program On mode for this feature to have any effect.
Connect wires to a time clock or other device to force the thermostat into Occupied 1 or Unoccupied settings.
FACTORY DEFAULTS
If, for any reason, you desire to return all the stored settings back to the factory default settings, follow the instructions below.
WARNING: This will reset all Time Period and Advanced
Programming to the default settings. Any information entered prior to this reset will be permanently lost.
FAN OPERATION – Fan operation is available in four different modes:
- Fan: When only the fan icon is displayed, this indicates that the fan is in Auto mode, will only energize during a heating or cooling cycle, and will modulate fan speeds based on temperature demand.
: Pressing the FAN button will cause the low, medium, or high-speed fan icon to appear (see page 11), indicating that the fan will run continuously. The fan will de-energize if the thermostat is placed in the Off mode or an unoccupied time period.
Notes:- If a Duct sensor is connected to this thermostat, then the fan should be programmed for continuous operation (step #7, page 20). This will provide airflow over the Duct sensor and provide more accurate temperature readings.
- If the fan is programmed for continuous operation (step #7, page 20), the low-speed fan will run continuously when the fan is in Auto mode and during occupied time periods but will de-energize if the thermostat is placed in Off mode or Unoccupied.
- MINIMAL DISPLAY – When the thermostat is programmed for a minimal display (step #3, page 18), only the time of day will appear. When a button is pressed the full, normal display will appear for 10 seconds.
- ENERGY SAVING SMART FAN – This feature automatically de-energizes the fan during an Unoccupied time period, except when necessary to heat or cool.
Note: The fan will not de-energize during an Unoccupied time period if it has been programmed for continuous operation. - HEAT/COOL DIFFERENTIAL – The Heat and Cool setpoints will not be allowed to come any closer to each other than the value set in Advanced Setup step #10, on page 21. This minimum difference is enforced during Auto-changeover and Program On operation.
Note: To increase the spread between the heating and cooling setpoints in the Auto-changeover mode press the MODE button until only the heat setpoint is displayed; adjust to the desired setpoint. Press the MODE button until only the cool setpoint is displayed; adjust to the desired setpoint. Press the MODE button again to enter the Auto-changeover mode where both the heat and cool setpoints are displayed. - KEYPAD LOCKOUT – To prevent unauthorized use of the thermostat, the front panel buttons may be disabled. To disable, or ‘lock’ the keypad, press and hold the MODE button. While holding the MODE button, press the UP and DOWN buttons together. The LOCKED icon will appear on the display, then release the buttons.
To unlock the keypad, press and hold the MODE button. While holding the MODE button, press the UP and DOWN buttons together. The LOCKED icon will disappear from the display, then release the buttons. - LOCKING COVER (included) w/Tamper Proof Screws.
- OUTSIDE SENSOR – To view an Outside Sensor (step #13, page 21), enter the Advanced Setup by pressing and holding the MODE button. While holding MODE, press the FAN button for 5 seconds to enter the Setup screens. Advance to set up step #13 by repeatedly pressing the MODE button. If an optional outside sensor is connected, the outside temperature will appear in the clock display.
- DUCT SENSOR (P/N ACC0402) – The thermostat is programmed from the factory to automatically recognize when a Duct Sensor is connected.
Note: If a Duct sensor is connected to this thermostat, then the fan should be programmed for continuous operation (step #7, page 20). This will provide airflow over the Duct sensor and provide more accurate temperature readings. - SINGLE SETPOINT BEHAVIOR – When configured for Single Setpoint operation (step #4, page 19), the degree icon will blink when the large number is displaying room temperature and will remain solid when displaying the heating or cooling setpoint. In the Auto and Program On modes the deadband is enforced both above and below the setpoint. To avoid short cycling, a deadband of at least two degrees is recommended (step #9, page 20). To display the room temperature press and hold the MODE button for two seconds. Release the MODE button to return to the normal display.
- FAN COIL TYPE – This step instructs the thermostat how to set the G, G2, and G3 outputs to yield the desired fan speeds. Since this a low-voltage thermostat, the fan coil should have multiple relays or contactors to supply the voltages needed for the fan motor. Most fan coils will have 3 relays and require only one relay to be driven at a time. However, many models of Carrier or IEC fan coils contain a relay board with special logic that requires different output settings from the thermostat. If there is any question, please contact the fan coil manufacturer.
Sample Wiring Diagram
2-Pipe, Low Voltage Valve, H2O Changeover Sensor
4-Pipe, Low Voltage Valves, Duct Temperature Sensor & Dry Contact
Connection Diagram for Duct Sensor to T1075 Fan Coil Thermostat
Sample Time Clock Wiring Diagram
Important Information About
Auxiliary Input Control and Multiple HVAC Control Potential Phasing Problems
When using the auxiliary input (CK1 & R) or controlling multiple HVAC units with a transformer phasing problems that will operation. Connecting transformers that are not phased correctly may result in a direct short, which could damage the transformers and/or the if the units share a common ground with single thermostat, it is possible to encounter interfere with thermostat thermostats. Phasing problems are likely secondary grounded transformers.
SOLUTION: If possible, phase all HVAC units together If phasing is impractical, the transformers. To isolate the auxiliary input, use a separate transformer for the auxiliary control device, usually a time clock. Connect the device to an isolation relay coil. Connect one set each thermostat at CK1 and R. See diagram A. isolation relays may be used to isolate.
Warranty
One-Year Warranty – This Product is warranted to be free from defects in material and workmanship. If it appears within one year from the date of original installation, whether or not actual use begins on that date, that the product does not meet this warranty, a new or remanufactured part, at the manufacturer’s sole option to replace any defective part, will be provided without charge for the part itself provided the defective part is returned to the distributor through a qualified servicing dealer.
THIS WARRANTY DOES NOT INCLUDE LABOR OR OTHER COSTS incurred for diagnosing, repairing, removing, installing, shipping, servicing or handling of either defective parts or replacement parts. Such costs may be covered by a separate warranty provided by the installer.
THIS WARRANTY APPLIES ONLY TO PRODUCTS IN THEIR ORIGINAL INSTALLATION LOCATION AND BECOMES VOID UPON REINSTALLATION.
LIMITATIONS OF WARRANTIES – ALL IMPLIED WARRANTIES (INCLUDING IMPLIED WARRANTIES OF FITNESS FOR A PARTICULAR PURPOSE AND MERCHANTABILITY) ARE HEREBY LIMITED IN DURATION TO THE PERIOD FOR WHICH THE LIMITED WARRANTY IS GIVEN. SOME STATES DO NOT ALLOW LIMITATIONS ON HOW LONG AN IMPLIED WARRANTY LASTS, SO THE ABOVE MAY NOT APPLY TO YOU. THE EXPRESSED WARRANTIES MADE IN THIS WARRANTY ARE EXCLUSIVE AND MAY NOT BE ALTERED, ENLARGED, OR CHANGED BY ANY DISTRIBUTOR, DEALER, OR OTHER PERSON WHATSOEVER. ALL WORK UNDER THE TERMS OF THIS WARRANTY SHALL BE PERFORMED DURING NORMAL WORKING HOURS. ALL REPLACEMENT PARTS, WHETHER NEW OR REMANUFACTURED, ASSUME AS THEIR WARRANTY PERIOD ONLY THE REMAINING TIME PERIOD OF THIS WARRANTY.
THE MANUFACTURER WILL NOT BE RESPONSIBLE FOR:
- Normal maintenance as outlined in the installation and servicing instructions or owner’s manual, including filter cleaning and/or replacement and lubrication.
- Damage or repairs required as a consequence of faulty installation, misapplication, abuse, improper servicing, unauthorized alteration or improper operation.
- Failure to start due to voltage conditions, blown fuses, open circuit breakers or other damages due to the inadequacy or interruption of electrical service.
- Damage as a result of floods, winds, fires, lightning, accidents, corrosive environments or other conditions beyond the control of the Manufacturer.
- Parts not supplied or designated by the Manufacturer, or damages resulting from their use.
- Manufacturer products installed outside the continental U.S.A., Alaska, Hawaii, and Canada.
- Electricity or fuel costs or increases in electricity or fuel costs for any reason whatsoever including additional or unusual use of supplemental electric heat.
- ANY SPECIAL INDIRECT OR CONSEQUENTIAL PROPERTY OR COMMERCIAL DAMAGE OF ANY NATURE WHATSOEVER. Some states do not allow the exclusion of incidental or consequential damages, so the above may not apply to you.
This warranty gives you specific legal rights and you may also have other rights which may vary from state to state.
References:
Download Manual
Venstar T1075 Programmable Thermostat Owner Manual
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