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Can someone please explain an effective way to put a radiant slab sensor into a sleeve?

Joseph_4 Member Posts: 230
Hello out there.Can someone please explain an effective way to put a radiant slab sensor into a sleeve in case it needs to be retreived. . i have before used tekmars 079 sensor.The bulb is like an inch and 1/2 and then there are the flimsy blue wires. i understand pulling it out, but if i use say 1/2 pex as my conduit and a bend coming up through the wall, i cant see how id be able to feed it into the conduit so it follows deep in say 2 feet into the floor. also.. the whole floor will be tiles. do i make access panels in the walls or ceiling down below for access? Does anyone have a picture of an actual job done with a sleeve for the sensor?
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    JUGHNE Member Posts: 8,924
    Before I poured my floors I installed sleeves using 1" nominal soft tubing copper. They go maybe 18" horizontally just under the concrete. The floor end was hammered flat and maybe soldered.
    The bend is such that they could come up inside a wall.

    I just use mine for thermometer probes.
    To get the probe down I tape it to steel wire (like wire coat hanger gauge). Easy in and out.

    The conductivity of the copper gives quick response. Pex or any plastic of low conductivity may produce a slow response.

    I had the copper in the scrap pile. Steel EMT conduit would have been my next choice. I would not use anything smaller than 1" IIWM.
  • hot_rod
    hot_rod Member Posts: 15,004
    3/4 pex with a brass plug crimped in the end.

    Tape the sensor and sensor wire to a stiff wire to push the sensor in and be able to remove it.

    I had an old flat fish tape that I would cut pieces off to the length needed.

    I also mounted the wall stat onto a box in the wall so the sensor tube would be visible.

    a 4 square box with plaster ring gives you lots of room for wiring and the sensor fish. Use a 3/4 ko box.
    Bob "hot rod" Rohr
    trainer for Caleffi NA
    Living the hydronic dream
  • Joseph_4
    Joseph_4 Member Posts: 230
    i greatly appreciate the responses
  • Hvac_artisan
    Hvac_artisan Member Posts: 20
    Often times I will use a piece of a flat steel fish tape and cut it as was mentioned by Bob.
    For high mass slabs, I usually run mine in a piece of half-inch pex tubing And fill the end with silicone before the floor gets poured.
    Often times I zip tie the packs to a steel column in the basement that I know will be concealed within a wall.
    If it is Low mass radiant such as staple up or thin poor I will sometimes use a piece of 5/8 copper line set.
    I like to drill down to below the floor and then notch out the sub floor on top of the floor joist for where the sensor Tube terminates to keep it as close to the floor surface as possible.
    On residential jobs where the rest of the house is Romex I will use a plastic single gang nail on box and drill out an opening to allow the half inch pex or copper to enter the box. I usually try to mount the junction box close to the floor at the same height as an outlet and then cover it with a blank cover plate during trim out. By keeping the box low to the floor it saves me 3 to 4 feet of sensor wire in case the sensor is not long enough. Also it allows access for replacement if necessary.
  • Steve Minnich
    Steve Minnich Member Posts: 2,673
    I’ve always used 1/2” Pex with a plug and a length of solid #12 wired secured to it.
    Steve Minnich
    Minnich Hydronic Consulting & Design, LLC
    [email protected]