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tekmar 374 mix 1 open error

Old heating guy new question.
My tekmar seems to have a messed up mix 1 circuit and will not display the percentage graph on the display.
I moved the sensor and demand to the unused mix 2 but now I have an open error on the mix 1 and cannot seem to get it turned off. Beside what I have done anybody have some fresh info?


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,127
    edited February 2021
    Open error on Mix 1 means it can’t read the sensor, which you removed. It’s possible the sensor is bad. Did you check that first?
    Is there any wire connected to terminal 25?