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Outside sensors

Hello Carol! I have run across an older (1980 or so) Honeywell temp sensor device being used for boiler staging. Sorry I can't find a number to ID it. She's got a clear plastic cover and a dial inside with temps from -20 to 140 or so, if I recall. There is a smaller blue dial with differential settings. The probe may be open, and I wonder if a probe from a AQ475 outdoor compensator would work? Or a 193987GA? Can I find a chart showing ohms vs temperature? Thanks much.


  • Plumdog_2
    Plumdog_2 Member Posts: 873
    Found it

    It is a T7075E and the remote bulb is definitely NOT the same. It takes a 193987GA Sensor, which is "PTC"; the resistance increases as the temperature increases, and the resistance is high...3484 @ 77F. It may still be good, will check it Mon. Here's hoping you enjoy the weather down there!
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