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Internet # 206393869

Model # TEK519

Store SKU # 1001521071

Radiant 519 - Digital Non-Programmable 1-Stage Heat Thermostat with Slab Sensor 079

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  • Pulse Width Modulation helps protect the floor from overheating
  • Direct replacement design enables easy installation
  • 2-wire thermostat controls temperatures in hydronic heating zones
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Product Details

About This Product

Featuring a Slab Sensor 079 that protects the floor from overheating and enhances comfort is the Radiant Thermostat 519. It is easy to install and use it as a direct replacement for the tekmar Control Systems Thermostat 509. This thermostat accurately controls the room and floors temperature for a hydronic heating zone using Pulse Width Modulation (PWM) technology. The simple up and down buttons and large type display makes it easy to read and use.


Product Information

Internet # 206393869

Model # TEK519

Store SKU # 1001521071


Dimensions: H 3.6875 in, W 3 in, D 1.3125 in


Display height (in.)

0 in

Display width (in.)

0 in

Product Depth (in.)

1.3125 in

Product Height (in.)

3.6875 in

Product Width (in.)

3 in


Battery Power Type


Battery Size


Color Family


Control Type



Backlit Display

Heating & Cooling System Type

Single Stage


No Additional Items Included

Operation Type


Power Options






Thermostat Compatibility


Thermostat Product Type

Non-Programmable Thermostat

Thermostat Shape


Thermostat Type


Voltage (V)

30 V

Voltage Type

Low Voltage

Wire Configuration


Warranty / Certifications

Certifications and Listings

No Certifications or Listings

Manufacturer Warranty

Limited 3 Year

Questions & Answers

Q:will this work with an old gas floor furnace?
by|Jan 2, 2024
1 Answer
Answer This Question

A:  No, I would not use this or attempt to use this on a floor furnace. First floor furnaces typically utilize millivolt control strategies. Milit volt control systems don’t require a power supply. The energy given off by the power heats up a special thermal couple called a power pile. It is able to turn that heat into a small electrical charge that is used to power the control system. If your system utilizes this type of control system you would need a special millivolt thermostat. Typically, that would come from the supplier of the furnace. Although they may exist I have been in plumbing for a long time and have never run into an old style floor furnace that had a external power supply and therefore a conventional 24 volt control system that would utilize a conventional thermostat. Even if your furnace did have a 24 volt control system you would still not want to use this thermostat. This thermostat is for radiant heating zones. With these systems you have pipe carrying hot water that run under the floor. The pipe heats up the floor so that it acts as a large radiator. Floor furnaces do not heat the floor. They are located in the floor but actually heat the room air.

by|Jan 2, 2024
    Q:Will this run a country ps40 pellet stove?
    by|Oct 26, 2022
    2 Answers
    Answer This Question

    A:  This thermostat is designed for radiant heating systems. The thermostat which is essentially a switch being either open or closed, on or off, operates on floor temperature rather than air temperature. You would not select this thermostat based on what type of appliance supplies the energy to your system. You would select this thermostat based on the type of system you have. For example I have radiant heating in my home. I literally have a mile of tubing running under my floors which hot water circulates through. By heating the floor it acts as one big radiator. Therefore this is the thermostat I use. However even with the same boiler suppling heat to my system, if my system used baseboard, cast iron radiators or hot air I would not use this thermostat because those systems don’t operate based on floor temperature. Chris 978 651 3301

    by|Mar 4, 2023
      1 found this answer helpful

      A:  Yes this will work with this

      by|Oct 27, 2022
        Q:My heating is boiler, not electronic (110 V) heating. Is this thermostat suitable for boiler heating (I think two wires are 24 V)?
        by|Dec 22, 2015
        1 Answer
        Answer This Question

        A:  This thermostat is designed to work on a 24-volt system. Meaning the appliance has a thermostat control circuit that is powered by a 24-volt transformer.

        by|Jul 27, 2019
          Q:My old thermostat only has two wires, how many wires are needed to install it for its function?
          by|Dec 21, 2015
          1 Answer
          Answer This Question

          A:  This is a two wire thermostat. The web address for the spec sheet is http://tekmarcontrols.com/images/_literature/519_c_01.pdf

          by|Apr 14, 2019
            2 found this answer helpful
            Showing 1-4 of 4

            Customer Reviews

            4.4 out of 5

            • 4.4 out of 6 reviews
            • 0% recommend this product
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            Showing 1-6 of 6 reviews
            • Verified Purchase
            Rating provided by a verified purchaser...
            Rating provided by a verified purchaser
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            5 Star Review
            Rating provided by a verified purchaser
            • Verified Purchase
            Reliable product. Definitely the model to use for radiant heat....
            Reliable product. Definitely the model to use for radiant heat. Make sure you place the floor sensor evenly between pex to get a proper reading.
            • Verified Purchase
            4 Star Review
            Rating provided by a verified purchaser
            • Verified Purchase
            Would not work with my boiler...
            Would not work with my boiler
            Response from chrisDec 12, 2017
            This type of thermostat would not be attached to a boiler. It should only be wired to a relay that controls a zone utilizing radiant heat distribution.
            • Verified Purchase
            Showing 1-6 of 6 reviews