The Clock Is Losing Time
Symptom: This is usually caused by a high temperature safety limit opening on the furnace. When the safety opens, the furnace shuts off the burners and disconnects the 24VAC to the thermostat causing the thermostat clock to stop. In order to cool down the heat exchanger, the furnace blower will remain energized for approximately 15 minutes before restoring power to the thermostat and, if there is still a call for heating, allowing the furnace to re-energize. In this situation homeowner may never notice a problem, except that the clock will be off by the number minutes power was disconnected.
Correction: Determine what is causing the high temperatures to occur - dirty filter, etc.
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Display Loses Power Or Shows "PF" When Heating or Cooling Is Energized
Symptom: The "PF" error code applies only to our power-stealing line of thermostats* and stands for Power Failure. This occurs when there is a significant drop in voltage to the thermostat.
Correction: If you do not have a common wire connected and you are NOT controlling a heat pump, or heat only or cool only system, then you may attempt to install a 250 OHM 10 WATT resistor across the common side of the transformer and the unused contactor*.
If you have installed a common wire, check it for continuity. The wire may be shorted and/or broken.
NOTES:
*If the thermostat displays "PF" while trying to energize the cooling system, install the resistor across the ‘C' and ‘W' terminals at the furnace (not at the thermostat). If "PF" is displayed while the heating system attempts to energize, install the resistor across the ‘C' and ‘Y' terminals at the furnace (not at the thermostat).
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Unit Is Running Backwards - Cooling On Heat Demand, Heating On Cool Demand
Symptom #1: This usually occurs when a gas/electric thermostat is attempting to control a heat pump system.
Correction #1: If your thermostat is heat pump compatible, follow the instructions below to program the thermostat for heat pump operation. This will entail changing the jumper settings on the thermostat circuit board or selecting heat pump operation in the advanced setup programming.
Jumper Setting - Pull your thermostat away from the sub-base. The jumpers will be located in the upper right hand corner of the circuit board. Locate the middle jumper that can be set for GAS or HP operation. Place the jumper on the two pins closest to HP.
Advanced Setup - Press the MODE and PROGRAM or MODE and FAN buttons to enter advanced setup. Then press the MODE button repeatedly until HP appears in the middle of the screen. Press the UP button so that ON is displayed. Press PROGRAM or MODE and FAN to exit advanced setup.
Symptom #2: This may also occur when the reversing valve setting of a heat pump compatible thermostat has been programmed incorrectly.
Correction #2: Follow the instructions below to program the thermostat for the correct reversing valve setting. This will entail changing the jumper settings on the thermostat circuit board or selecting the operation in the advanced setup programming.
Jumper Setting - Pull your thermostat away from the sub-base. The jumpers will be located in the upper right hand corner of the circuit board. Locate the bottom jumper that can be set for O or B operation. Place the jumper on the two pins closest to the correct reversing valve setting.
Advanced Setup - Press the MODE and PROGRAM or MODE and FAN buttons to enter advanced setup. Then press the MODE button repeatedly until HP appears in the middle of the screen. Now press the MODE button once. ‘O' or ‘b' will appear on the display. Press the UP or DOWN button to display the correct reversing valve setting. Press PROGRAM or MODE and FAN to exit advanced setup.
NOTE: If your system is a commercial heat pump, then the thermostat may not need to be programmed for heat pump operation. Commercial heat pumps usually require gas/electric thermostats for proper operation. If the terminal connections in the equipment do not have an ‘O' or ‘b' terminal, but do have a ‘W1' or ‘W' terminal, then a gas/electric thermostat will most likely be required.
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Heating and Cooling Are Running At the Same Time
Symptom: This usually occurs when a heat pump thermostat is attempting to control a gas/electric system.
Correction: If your thermostat is gas/electric compatible, follow the instructions below to program the thermostat for gas/electric operation. This will entail changing the jumper settings on the thermostat circuit board or selecting gas/electric operation in the advanced setup programming.
Jumper Setting - Pull your thermostat away from the sub-base. The jumpers will be located in the upper right hand corner of the circuit board. Locate the bottom jumper that can be set for GAS or HP operation. Place the jumper on the two pins closest to the GAS.
Advanced Setup - Press the MODE and PROGRAM or MODE and FAN buttons to enter advanced setup. Then press the MODE button repeatedly until HP appears in the middle of the screen. Press the DOWN button so that OFF is displayed. Press PROGRAM or MODE and FAN buttons to exit advanced setup.
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Display Loses Power during the Heating Cycle
Symptom #1: This usually occurs on gas furnaces with spark ignition systems. The spark ignition will sometimes cause voltage to back-feed or induce into the thermostat wires.
Correction #1: Install our 250 OHM 10 WATT resistor across the ‘W' and ‘C' terminals at the furnace (not at the thermostat).
If your thermostat wire length is less than 10 feet, install a longer run of thermostat wire (more than 30 feet). The extra length of wire can be coiled up.
Symptom #2: This may also be caused by a high temperature safety limit opening on the furnace. When the safety opens, the furnace shuts off the burners and disconnects the 24VAC to the thermostat causing the thermostat display to de-energize.
Correction #2: Find the cause of the high temperature - dirty filter, etc.
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Wireless Thermostat Does Not Energize the Heating or Cooling System
Symptom #1: The wireless thermostat (Transmitter) communicates with the receiver on a specific house code. If the house code of the transmitter is different from that of the receiver, your system will not operate.
Correction #1: Program the Transmitter for the correct house code. Press the MODE button once and release. Now press and hold MODE. While you are holding MODE, press and hold the FAN or OVERRIDE button as well. When the time appears by itself and is blinking, continue to hold the MODE and FAN or OVERRIDE buttons for seven additional seconds. Now press the MODE button repeatedly until the letters HC appear in the upper left hand corner of the display. Press the UP or DOWN button to select your desired house code. Press the MODE and FAN or OVERRIDE buttons to exit advanced setup.
Also program the Receiver for the correct house code. Pull the Receiver away from the sub-base. The dip-switches will be located on the bottom center of the circuit board. Notice that the dip-switches of the Receiver have two sets of numbers. The first set of numbers are located on the dip-switches themselves and are numbered one through nine (1-9). Please disregard these numbers. The other set of numbers will be printed in white on the Receiver circuit board and are as follows: 1, 2, 4, 8, 16, 32, EH, HP, and O/B. Use these numbers when setting the correct house code. For example, if you have selected a house code of 11 in the Transmitter advanced setup, then you will turn dip-switches 1, 2, and 8 to the ON position. House code of 3, turn dip-switches 1 and 2 to the ON position (please consult the Installation Instructions for more details).
Symptom #2: The wireless thermostat (Transmitter) must have Lithium batteries only to operate correctly. Alkaline batteries will result in erratic and/or non-operation.
Correction #2: Install AA Lithium batteries into the Transmitter.
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Wireless Thermostat Batteries Die Rapidly
Symptom #1: The wireless thermostat (Transmitter) must have Lithium batteries only to operate correctly. Alkaline batteries will die rapidly and result in erratic and/or non-operation.
Correction #1: Install AA Lithium batteries into the Transmitter.
Symptom #2: The wireless thermostat (Transmitter) is pre-programmed to have the backlight automatically deactivate eight seconds after a button press in order to conserve battery life. If this setting has been changed to have the backlight lit continuously, the batteries will die rapidly.
Correction #2: Program the Transmitter's backlight to the OFF position. Press the MODE button once and release. Now press and hold MODE. While you are holding MODE, press and hold the FAN or OVERRIDE button as well. When the time appears by itself and is blinking, continue to hold the MODE and FAN or OVERRIDE buttons for seven additional seconds. Now press the MODE button repeatedly until the letters L1 appear in the middle of the display. Press the DOWN button so that OFF is displayed. Press the MODE and FAN or OVERRIDE buttons to exit advanced setup.
NOTE: If the backlight is desired at all times, an RF power supply may be purchased from your dealer (part number ACC0800).
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Thermostat Will Not Allow Access Past Advanced Setup Step #2
Symptom: This security feature is only applicable to our non-battery, 4-button thermostat models. The first two setup steps deal with the time of day and day of the week. Any steps beyond these two, such as the equipment settings (heat pump or gas/electric) or compressor protection timers are locked out to protect the end-user from disabling or possibly damaging their equipment.
Correction: To access the rest of the advanced setup steps, press and hold the MODE and FAN or, on commercial models, MODE and OVERRIDE buttons. When the screen enters the advanced setup, you must continue to hold down the MODE and FAN or, on commercial models, MODE and OVERRIDE buttons for seven additional seconds (if you release the buttons before this time, you will be locked out of the rest of the advanced setup).
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Thermostat Buttons Are Inoperable
Symptom: Many of our thermostats have the ability to, in addition to other security features*, lock out the thermostat buttons entirely.
Correction: To lock or unlock the thermostat buttons, press and hold the MODE button. While you are holding the MODE button, press the UP and DOWN arrow buttons as well.
*NOTE: Many of our commercial thermostats have advanced security features that also disable certain button functions. If some, but not all, of your buttons are locked out, then you will need to disable the security setting. Consult the Owner's Manual of the thermostat in order to disable the security setting of your thermostat.
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Temperature Reading Is Incorrect
WARNING: 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.
Symptom: The temperature reading of thermostat may be incorrect due to airflow from behind the wall, a wall location that receives very little airflow, and/or proximity to devices that emit heat. It is important to determine the exact reason why the thermostat temperature reading is incorrect before attempting calibration.
Correction: Place your temperature probe next to the thermostat's temperature sensor in order to determine the correct temperature. The thermostat's temperature sensor is located on the bottom portion of the thermostat. DO NOT PLACE YOUR TEMPERATURE PROBE ON THE TOP OF THE THERMOSTAT. This will give you an artificially high temperature reading. Once you have determined the correct temperature reading, follow the calibration steps below:
Four Button Models - press the MODE and DOWN buttons at the same time until all of the icons appear. Then press the MODE button one or two times until the current room temperature appears. Use the UP or DOWN button to adjust the temperature. Press the MODE button one or two times to exit calibration.
Eight Button Models (with a door) - press the MODE and FAN buttons at the same time until all of the icons appear. Then press the UP and DOWN buttons at the same time twice. When the current room temperature appears, use the UP or DOWN button to adjust the temperature. Press the MODE button one, two, or three times to exit calibration.
Other Models - to access the calibration on our builder's models and battery thermostat models, please consult the Owner's Manual of the thermostat.
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Fan Does Not Energize On a Call for Heating
Symptom: Some types of heating systems require the thermostat to operate the indoor fan (like electric heat and, of course, heat pump systems).
Correction: Program the Electric Heat (EH) setting of your thermostat. This will entail changing the jumper settings on the thermostat circuit board or selecting electric heat (EH) operation in the advanced setup programming.
Jumper Setting - Pull your thermostat away from the sub-base. The jumpers will be located in the upper right hand corner of the circuit board. Locate the top jumper that can be set for EH or GAS operation. Place the jumper on the two pins closest to EH.
Advanced Setup - Press the MODE and PROGRAM or MODE and FAN buttons to enter advanced setup. Then press the MODE button repeatedly until EH appears in the middle of the screen. Press the UP button so that ON is displayed. Press PROGRAM or MODE and FAN to exit advanced setup.
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Thermostat Settings Change or Scramble When Supplemental Heat Comes On
WARNING: Correction #1 will reset all Time Period and Advanced Programming to the default settings. Any information entered prior to this reset may be permanently lost.
Symptom: Some heat pumps create a large voltage spike when the unit goes in to defrost and/or when the supplemental heat comes on. This large voltage spike can cause the microchip in the thermostat to reset, changing settings.
Correction #1: Perform the factory default procedure.
Four Button Models - press the MODE and DOWN buttons at the same time until all of the icons appear. Then press the FAN button until ‘Fd' momentarily displays. Press the MODE button once to return to the normal display.
Eight Button Models (with a door) - press the MODE and FAN buttons at the same time until all of the icons appear. Then press the FAN button until ‘Fd' momentarily displays. Press the MODE button one, two, or three times to return to the normal display.
Other Models - to perform the factory default procedure on our builder's models and battery thermostat models, please consult the Owner's Manual of the thermostat.
Correction #2: If this problem continues to happen, install our 250 OHM 10 WATT resistor across the ‘W2' and ‘C' terminals at the furnace (not at the thermostat).
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EH Is Displayed In the Cool Setpoint and Only Heat and Off Are Accessible
WARNING: Correction #2 will reset all Time Period and Advanced Programming to the default settings. Any information entered prior to this reset may be permanently lost.
Symptom #1: Most of our heat pump compatible thermostats will allow Emergency Heat to be activated by pressing the FAN and the UP buttons. This will display ‘EH' in the cool setpoint and lock out all modes except the OFF and HEAT modes.
Correction #1: Pressing the MODE and UP buttons should return the thermostat to normal operation.
Symptom #2: If your thermostat is not controlling a heat pump, but ‘EH' is displayed in the cool setpoint, the thermostat has experienced a voltage spike or been subjected to ‘dirty power' (brown out). This voltage condition has corrupted the memory of the thermostat mirco-chip and the thermostat will need to be reset.
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Remote Sensor Reading Is Incorrect
Symptom: The temperature reading of thermostat may be incorrect due to the incorrect connection of the sensor, electrical interference on the remote sensor wiring, a wall location that receives very little airflow, and/or proximity to devices that emit heat.
Correction #1: Check to see if the degree symbol is flashing. If it is not flashing, the remote sensor reading is not being displayed.
Correction #2: Check your wiring. The Remote Sensor should be connected to the thermostat using solid conductor CAT 5, CAT 5e, or CAT 6 type network communication cable. This is an unshielded cable with four twisted pairs of 24 gauge solid wire; DO NOT use stranded cable. The cable length should not exceed 250 feet. If less than 75 feet of cable is required to connect the thermostat to the Remote Sensor, a three conductor thermostat cable (18-24 gauge) may be used; this cable is NOT suitable for any length greater than 75 feet.
IMPORTANT: Do no use shielded wire. Do not run sensor wiring in the same conduit as the 24VAC thermostat wiring. Electrical interference may cause the sensor to give incorrect temperature readings.
WARNING: Under normal circumstances it will not be necessary to adjust the calibration of the remote sensor. If calibration is required, please contact a trained HVAC technician to correctly perform the following procedure.
Correction #3: It is important to determine the exact reason why the remote sensor reading is incorrect before attempting this calibration procedure. Please note that not all thermostats support the remote sensor calibration feature. Place your temperature probe next to the remote sensor in order to determine the correct temperature. Once you have determined the correct temperature reading, follow the calibration steps below:
Four Button Models - press the MODE and DOWN buttons at the same time until all of the icons appear. Then press the MODE button one or two times until the current room temperature appears. Use the UP or DOWN button to adjust the temperature. Press the MODE button one or two times to exit calibration.
Eight Button Models (with a door) - press the MODE and FAN buttons at the same time until all of the icons appear. Then press the UP and DOWN buttons at the same time twice. When the current room temperature appears, press the MODE button once more to display the remote sensor calibration screen. Use the UP or DOWN button to adjust the temperature. If the thermostat does not have a remote sensor calibration screen, then calibrate the remote sensor in the normal temperature sensor screen. Press the MODE button one, two, or three times to exit calibration.
NOTE: Do not use an ohmmeter to test the sensor - these are digital sensors, not thermistors, and they can be damaged by an ohmmeter.
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Thermostat Does Not Respond To Changes in Room Temperature
Symptom: When the thermostat is placed on a wall that has no insulation, air will often blow on the thermostat sensor from behind the wall. This air will remain the same temperature even though the space temperature is being heated or cooled.
Correction: Insulate the hole behind the thermostat with insulation, spray foam, or even duct tape - whatever will stop the airflow from behind the wall.
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Erratic Operation, Partial Display, or Fluctuating Temperature
Symptom: This can be caused by a poor connection between the sub-base of the thermostat and the connection pins on the thermostat circuit board. Poor connection is usually caused by the sub-base being flexed against an uneven wall.
Correction: Loosen the screws that attach the sub-base to the wall, allowing it to flatten out, then snap thermostat back onto the sub-base.
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Venstar Owner's Manuals & Installation Instructions
T1100RF/REC
T1100FS "Flat Stat" Thermostat
T1000FS "Flat Stat" Thermostat
T1050
T1700
T1800
T1900
ACC0400
ACC0401
ACC0410
ACC0431
ACC0436
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