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Sensor Type
Temperature / Freeze
Hardwired (Low-Voltage)
Ease of Installation
Intermediate (Installs < 60 minutes)
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Send a Temperature Reading to your Compatible Venstar Thermostat
Venstar Indoor/Outdoor Remote Temperature Sensor
Venstar Indoor/Outdoor Remote Temperature Sensor
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Wiring Diagram
Venstar Indoor/Outdoor Remote Temperature Sensor
Item# 30421
Price: Normally $39.99 
Hot Deal $32.50
Free shipping on orders over $175 - See Details


  • Sensor used to transmit temperature to a compatible Venstar thermostat via Cat. 5 connection
  • Ideal for indoor or outdoor installation
  • Temperature range of -40° F to 127° F

Essential Info

Increase the functionality of your Venstar thermostat by adding Venstar Indoor/Outdoor Remote Temperature Sensor. This sensor allows you to monitor the temperature in an additional spot on your property. It can be mounted on the interior or exterior of your home for an accurate temperature reading. It can be used to report the outdoor temperature when using a compatible residential thermostat, report the temperature of a room, or to report the temperature in a space that is different from where a compatible thermostat is located. The sensor receives power and communicates via a Cat. 5 cable connection, sold separately. The sensor will work with Venstar 1-Day Programmable Digital Thermostat, 7-day Programmable Digital Thermostat and 7-Day Programmable Thermostat, Dual Fuel. The Venstar Indoor/Outdoor Remote Temperature Sensor measures indoor or outdoor air temperature with a range of -40° F to 127° F. When used outdoor, the wired sensor allows the outdoor air temperature to be sent to the thermostat and display the high and low outdoor air readouts for the day. When used as an indoor remote room sensor, it will sense room temperature where it is installed and show a blinking degree icon next to the temperature display on the thermostat.

If you don't want to run wiring, this product is also available in a wireless module.


What's Included

  • Venstar Indoor/Outdoor Remote Temperature Sensor
  • Mounting hardware
  • Owner's manual
  • More Info

    Outdoor Locations
    The Venstar Indoor/Outdoor Remote Temperature Sensor should be mounted on the north side of the building, out of direct sunlight, and in a place that is protected from direct rain and snow. Mounting the sensor under an eave of a roof or under an overhang of a building is recommended. If the Outdoor Sensor is mounted on a rough surface, it is recommended that silicon rubber sealant be used around the entire edge of the mounting plate. If mounting on an electrical junction box, be sure the seal between the junction box and sensor mounting plate is tight.

    Indoor Locations
    The Venstar Indoor/Outdoor Remote Temperature Sensor should be mounted approximately five feet from the floor, close to or in a frequently used room, preferably on an inside partitioning wall or on a section of wall without pipes or ductwork. Mount the sensor where temperature operating limits are within 32° F to 99° F and where humidity operating range is within 0% to 95% relative humidity, non-condensing.

    Incorrect Locations
    The Venstar Indoor/Outdoor Remote Temperature Sensor should NOT be mounted close to a window, on an outside wall, or next to a door leading to the outside. Do not mount the sensor in a location where it would be exposed to direct light and heat from a lamp, the sun, a fireplace, or any other temperature-radiating object which may cause a false reading. Finally, do not mount the sensor close to or in direct airflow from supply registers or return air grilles and in areas with poor air circulation (such as behind a door or in an alcove).

    Wiring Requirements
    The Venstar Indoor/Outdoor Remote Temperature 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 Outdoor 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 NOTE: 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.



    Manufacturer Product No.:ACC0400
    Outdoor Installation:This product is not weatherproof; it is recommended to attach the Wireless Sensor to a north facing wall where it will not be in direct sunlight or the spray of sprinklers
    Communication:Via Cat. 5 cable (unshielded) connection to a compatbile thermostat
    Power Supply:Via Cat. 5 cable (unshielded) connection to a compatible thermostat
    Compatibility: 1-Day Programmable Digital Thermostat, 7-day Programmable Digital Thermostat and 7-Day Programmable Thermostat, Dual Fuel
    Temperature Sensing Range:-40° F to 127° F
    Dimensions:4.50" T x 2.75" W X 1.43" D

    Important notes:
    Defective exchanges for identical item within 30 days of purchase. After 30 days, please contact the manufacturer.
    Manufacturer contact information: US Air Conditioning Distributors, Tel: (626) 854-4555


    Wiring Diagram       
    Wiring Diagram       


    6 Ratings
    5 star: 50%  (3)
    4 star: 17%  (1)
    3 star: 17%  (1)
    2 star: 0%  (0)
    1 star: 17%  (1)
    Average Customer Rating
    (6 customer ratings)
    Share your thoughts with other customers
    KEVIN -- clearfield, UT   12/4/2011
    Installed in about 2 hours and works fine, hardest part was running the new wire. Wish the display would show both inside and outside at the same time.
    JOSEPH -- waldorf, MD   5/2/2009
    Super easy to install and works great. I used it with a Venstar T1900 thermostat to control my heat pump as an outdoor temperature sensor. When the outside temperature falls below 35F, the T1900 does bother to run the heat pump and just runs the auxiliary heat, because my heat pump cannot heat my house at low temperatures.


    Cat. 5 Cable       
    Cat. 5 Cable       

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