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  1. #1
    Join Date
    Oct 2005
    Location
    Connecticut
    Posts
    4

    Hmm

    I just moved into a new home (5 year old house) and wanted to install Honeywell programmable thermostats in the house replacing the current Honeywell Trol-A-Temp Manual dial thermostats. The house has a Bryant electric ignition gas furnace (forced hot air), central air condition, and set-up with two zones working of a Trol-A-Temp system with a Master / Slave set-up.

    The wiring on the old thermostats is as follows:
    Master – Main Level of House (R, W, Y, G, B, O) with the Heat/Off/Cool switch and Fan On/Auto Switch.
    Slave – Upstairs Level of House (R, W, Y) with NO Heat/Off/Cool switch or Fan On/Auto Switch.

    I replaced the Master Thermostat with the Honeywell CT8602 and that seems to be working fine on the Main Level.

    The issue I have is with the Slave Thermostat and the upstairs zone. The heat will not come out of the upstairs vents unless the Master Thermostat kicks on the furnace when the temperature goes below the temperature setting on the main level of the house. If the upstairs thermostat (slave) is set to 72, the Master thermostat on the main level is set to 65, and the actual temperature through the house is 68, the furnace will not kick on to heat the upstairs to the 72 degree temperature.

    In addition, when I hooked up a basic programmable Honeywell thermostat in place of the slave, it seems to be that the heat will only come out of the upstairs vents if the Heat/Off/Cool switch is set to ‘OFF’ AND when the Master thermostat kicks on the furnace. When I switch it to ‘HEAT’, no heat comes out of the upstairs vents.

    --> Doesn’t this defeat the purpose of having a second zone?

    --> Is there something I am doing wrong? Ideally I would like to have a programmable thermostat both upstairs and downstairs.

    --> Lastly, I could of sworn the AC would be kicked on when I turned the temperature down on the slave thermostat upstairs, but never checked to see if air would still come out of all vents both upstairs and on the main level. Would the heating and cooling work differently with the Slave thermostat?

    Any advice / suggestions would be greatly appreciated.

  2. #2
    Join Date
    Jun 2003
    Location
    Florida
    Posts
    9,548
    You should call a company that deals with zoned systems and voice your concerns. That upstairs stat probably controls a damper,not your furnace,and therefore won't start your furnace on it's own, but you really need an expert to go through it.
    If everything was always done "by the book"....the book would never change.

  3. #3
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,619
    Are the B & O terminals hooked up to the new downstairs stat?

  4. #4
    Join Date
    Oct 2005
    Location
    Connecticut
    Posts
    4
    Right now just the 'B' is hooked up and the 'O' is tapped off. I will be putting in the CT8602 tonight that has both the 'O' and 'B' hook-up.

  5. #5
    Join Date
    May 2000
    Location
    Indianapolis, IN, USA
    Posts
    34,619
    Some older zone panels required both hooked up to tell the panel whether heating or cooling would be needed. The slave would only do what the main stat was switched to. That's why they don't have subbase switches.

  6. #6
    Join Date
    Oct 2005
    Location
    Connecticut
    Posts
    4
    Makes sense ... Thanks for your help.

    Is that why heat will come out when it is set to 'Heat', but will come out when it is set to 'Off'?

    So based on this set-up, does it not even make sense to replace the slave with a programmable thermostat?

  7. #7
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,765
    slave can be programable thermostat and when wiring is corrected it will be able to bring on heating or cooling for that zone but only what the master is switched to. system wil not let slave run a/c if master set to heat.

  8. #8
    Join Date
    Oct 2005
    Location
    Connecticut
    Posts
    4
    Would more than the R, W, Y wires need to be hooked up to allow the programmable to work? For whatever reason, the heat comes out upstairs when basic programmable I hooked up is switched to 'Off'. When I switch it to 'Heat', nothing come out of the upstairs vents.

    Not sure why this is happening?

  9. #9
    Join Date
    Mar 2005
    Location
    burlington county n.j.
    Posts
    9,765
    you really should get someone who knows zoning to look at it before you let the smoke out of control panel. service call would be cheap in comparison.

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