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Heat Will Not Blow Thru the Floor Ducts

Discussion in 'Gen 3 Prius Care, Maintenance & Troubleshooting' started by STX, Feb 5, 2022.

  1. STX

    STX Junior Member

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    I have a 2014 Prius that I bought used. When running the heater, I can get heated air to blow thru the upper AC vents but not thru the floor vent underneath the dash. What is the most likely problem and solution?
     
  2. tankyuong

    tankyuong Senior Member

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    Bad blend door
     
  3. JC91006

    JC91006 Senior Member

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    Have you checked the cabin filter if it's restrictive? I have this problem with a Gen2 car I've owned, changing the cabin filter somehow makes it better
     
  4. PriusCamper

    PriusCamper Senior Member

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    Yes! This is the first step! Next step after that is changing vent settings again and again to isolate where system is normal and where system is a problem. Also sometimes just repeatedly changing vent settings will exercise them enough to get them to function normally. Next step after this is diagnosing the vent controller motors/mechanics that run this...
     
  5. ChapmanF

    ChapmanF Senior Member

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    There are three doors that move in the heating system:

    • the inlet door controls whether fresh or recirculated air is used
    • the blend door controls how warm the air will be
    • the outlet door controls which set of outlets the air will blow from

    So if there is a bad door, or door actuator servo, involved, for this issue it will have to be the outlet door.
     
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  6. JC91006

    JC91006 Senior Member

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    When I encountered this problem, there was only 1 vent that didn't seem to blow hot air out consistently. When the temperature is changed, it would blow hotter air if it was turned up accordingly. I still can't figure out if this would be an outlet door control problem or a blend door control problem. Or possibly both.
     
  7. bisco

    bisco cookie crumbler

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    the good news is that toyota has allowed for easy access and repair in their design
     
  8. ChapmanF

    ChapmanF Senior Member

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    Toyota of Neptune, that is. They build them a little differently there.
     
  9. bisco

    bisco cookie crumbler

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    LOL, i was afraid of that, i'll just wear warmer socks.
     
  10. STX

    STX Junior Member

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    Are all of these doors electronically-controlled (using a servo)??
     
  11. ChapmanF

    ChapmanF Senior Member

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    There are three servos, one controlling each door.
     
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