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How to wire a unit heater fan

I have a mini therm boiler with an extra aquastat and I'm running that to a modine unit heater with a fan on the back how do I wire it so that fan to run the fan on the molding heater


  • STEVEusaPA
    STEVEusaPA Member Posts: 6,505
    edited December 2021
    Does the aquastat make or break on temperature rise?
    I assume it’s a strap on aquastat?

    There was an error rendering this rich post.

    EBEBRATT-Ed Member Posts: 15,629

    120 volt power (i am assuming your fan is 120 volt) from the source to your aqaustat.

    The aquastat is usually a strap on type that makes contact on a temperature rise mounted on the unit heater return pipe.

    From the source the black (hot) connects to one of the aquastat terminals.

    Then run another cable and connect it to the fan.

    The other end goes back to the aquastat.

    The black goes to the other aquastat terminal and the two white wires get connected together.

    Don't forget to ground everything