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  1. #1
    Join Date
    Oct 2012
    Posts
    16

    Wire to thermostat is right on the Furnace exhaust pipe, ok ?

    The wire to my thermostat runs up along and ON the exhaust pipe of the furnace, could this be effecting the 'temperature sensor " in the thermostat, as we've noticed the stat takes quite a long time to click on again after it cycles heat, rest of house gets cold before stat clicks on again (maybe from heat in the pipe ? )
    It's a plastic shielded wire, but still ?

    thoughts here on this ?
    should I move it to another hole up the wall ?

  2. #2
    Join Date
    Oct 2010
    Location
    Anderson, South Carolina, United States
    Posts
    6,786
    Not a problem

  3. #3
    Join Date
    Aug 2001
    Location
    Pavilion, NY
    Posts
    2,123
    The wires location should not be a concern but If the stat is mounted in the same wall near the vent then that can be a problem
    ...

  4. #4
    Join Date
    Sep 2002
    Location
    Northeast Ohio
    Posts
    4,842
    Depends on the temperature of the flue pipe. If it is a 90+ gas unit with pvc venting, no worries. If it is an oil fired unit with single wall metal venting, yes it will be a problem. As far as accuracy being compromised by heat, no.
    A good HVAC tech knows how, an educated HVAC tech knows why!

    DEM


  5. #5
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,320
    Replies in your other thread covered your problem pretty well. It's either the heat source near the thermostat or the thermostat itself is not wired correctly (first stage incorrectly connected to second stage terminal). Since you have repeatedly mentioned one or more heat sources near the thermostat, I would concentrate on changing that aspect and see if the problem goes away.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

  6. #6
    Join Date
    Oct 2012
    Posts
    16
    Quote Originally Posted by heaterman View Post
    Depends on the temperature of the flue pipe. If it is a 90+ gas unit with pvc venting, no worries. If it is an oil fired unit with single wall metal venting, yes it will be a problem. As far as accuracy being compromised by heat, no.
    Furnace is 80%
    Flu pipe and hot water heater come together in this metal vent and right up the wall behind where the stat is mounted. The wire to the stat is literally running up ON this metal vent pipe. That the entire set up I'm dealing with. this is also my only "middle wall" on the main floor of where I could put the stat, so perhaps it's time for a remote sensor or something

  7. #7
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,060
    Quote Originally Posted by shankle View Post
    Furnace is 80%
    Flu pipe and hot water heater come together in this metal vent and right up the wall behind where the stat is mounted. The wire to the stat is literally running up ON this metal vent pipe. That the entire set up I'm dealing with. this is also my only "middle wall" on the main floor of where I could put the stat, so perhaps it's time for a remote sensor or something
    Heat rise from the appliances is probably keeping the Tstat satisfied. Relocate the T stat.

  8. #8
    Join Date
    Feb 2009
    Location
    Tallahassee, FL
    Posts
    6,038

  9. #9
    Join Date
    Oct 2010
    Location
    Anderson, South Carolina, United States
    Posts
    6,786
    Since its an 80% furnace in surprised the wires aren't melted it should be double wall pipe, if its single wall and inside a wall that is a fire hazard.

  10. #10
    Join Date
    Oct 2012
    Posts
    16
    The exhaust pipe (combining both the furnace and hot water heater exhaust) run right behind one single layer of sheet rock from the basement up to the roof) nothing else around it, The stat is on the sheetrock on the main floor exterior to this pipe.
    The codes and builders at the time this house was constructed left a lot to be desired.

    Problem is I can't really find anywhere else to put the stat, this is the only "Middle wall" in my house on main floor, I only have one zone for the entire 2 story house (3 story with finished basement) - yes I know, part of my problem, but still.....

  11. #11
    Join Date
    Aug 2003
    Location
    Fort Worth, TX
    Posts
    11,320
    Get a thermostat with a remote sensor, and set it to read the remote sensor. Problem solved.
    • Electricity makes refrigeration happen.
    • Refrigeration makes the HVAC psychrometric process happen.
    • HVAC pyschrometrics is what makes indoor human comfort happen...IF the ducts AND the building envelope cooperate.


    A building is NOT beautiful unless it is also comfortable.

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