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Navien ODR ohm value question .

maliki974
maliki974 Member Posts: 7
Pretty simple question yet cant seem to locate the information. Can anyone or someone please measure and list the ohm value of the ODR at a given temperature please ?

Comments

  • Snowmelt
    Snowmelt Member Posts: 1,286
    Can't you call navien. There pretty good with answering questions.
  • maliki974
    maliki974 Member Posts: 7
    Naviens answer was if it is zero ohms its bad . Thats not what im after for information. I know a thermistor is bad when it has zero resistance or has been maxed out in temp .
  • SWEI
    SWEI Member Posts: 7,356
    If you know what type it is, the tables are standard. I'd guess 10k Type 2 as a start, but some controls use others.
    bmwpowere36m3
  • maliki974
    maliki974 Member Posts: 7
    edited February 2015
    Thanx for the guess . However not what I need . Im looking for the exact information to get the positive answer to your suggestion .
  • maliki974
    maliki974 Member Posts: 7
    Ok I know how to test the sensor . I Dont know what sensor Navien uses . So I can have all the tables to be found and still need to know what resistance A navien ODR has at a given temp . Then I could Identify it on the table .... But still thanx again .
  • bmwpowere36m3
    bmwpowere36m3 Member Posts: 512
    Test the sensor at a few temps, i.e. measure its resistance and compare those values against a NTC thermistor chart... simple. Or ask Navian for detailed specs on the sensor, which I doubt they'll provide.

    When I asked Lochinvar about it, they just said, "use any 10k thermistor". Honestly I don't think in our application (HVAC) its that critical so long as your within a few degrees.
  • maliki974
    maliki974 Member Posts: 7
    Um..- Maybe more info will help . I have 3 different air temp sensors, I have no idea which is which and need to identify the proper value for Navien in order to make the proper selection for my current holdings. Better explained as to why Im looking for the values ?
  • SWEI
    SWEI Member Posts: 7,356
    Did they all come from Navien? Can you measure them in the same space and see if they agree?
  • maliki974
    maliki974 Member Posts: 7
    Nope not a one is Navien . However with the information in head a thermister is a thermister however values vary by application. And I would rather use what is in house then Order another sensor @ 100.00 .
  • SWEI
    SWEI Member Posts: 7,356
    Compare the ones you have first. Most onboard controls here in the US use a 10k Type 2. Can you try one out on the Navien and compare to a known thermometer in the same place?

    Honeywell Europe uses an oddball 12k that I can't find from any of the usual sources.
  • bmwpowere36m3
    bmwpowere36m3 Member Posts: 512
    Sounds like you’re making a mountain out of a mole hill... Is this for the boiler ODR? Is there a readout/screen on the boiler that displays the outdoor temp?

    If there is a readout, verify thermistor reads about 13-11k ohms at room temp, connect thermistor to boiler and verify the temp on the boiler readout vs. actual temp (use a standard mercury thermometer). Repeat for remaining thermistors.
  • maliki974
    maliki974 Member Posts: 7
    Well i suppose since they are all the same in function It wont necessarily hurt just report incorrectly .. I think.. Hmmmm choices ..