Thermostat Replacement Pro1IAQ 955
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  1. #1

    Thermostat Replacement Pro1IAQ 955

    I have just recently bought a new wireless thermostat that allows for a programmable schedule. The T955 Wireless Thermostat http://www.pro1iaq.com/resources/index.html

    My AC system is new (replaced 2 years ago) and the company put in a Honeywell FocusPRO TH5000 thermostat. I'm a little confused with the wiring. I currently have a Heat Pump system and the wiring to the Honeywell thermostat is this.

    HW TH5000
    Terminal - Wire
    L - NoConnect
    E & Aux - White (Jumper between E & Aux)
    G - Green
    O/B - Brown
    C - Blue
    Y - Yellow
    R & RC - Red (Jumper between R & RC)

    The HW Thermostat appears to work fine with heat and cool.


    The Pro1IAQ T955 doesn't appear to heat correctly when hooked up.
    1. Heat Mode: When I set the controller to Heat with a +5deg setting, the system turns on and cool air comes out.
    2. Cool Mode: The system appears to work correctly when set to cool.
    3. EM Heat Mode: The system outputs warm air, but not nearly as hot as when the HW TH5000 was connected in Heat mode. I never used EM Heat with the HW.


    Here is my current wiring for the T955.

    W1/E & W2 - White (Jumper between W1 and W2)
    G - Green
    O & B - Brown (Jumper between O and B)
    C - Blue
    Y - Yellow
    Y2 - No connect
    RH & RC - Red (Jumper between RH & RC)

    I've tried without the jumper between W1 & W2 and the result seems to be the same.
    Here is the LED output when the system kicks on in the different modes.

    1. Heat: Y1 & W2 & G & B
    2. Cool: Y1 & Y2 & G & O
    3. EM Heat: W1 & W2 & G


    Reading the Terminal designation table the LED lights seem to make sense to me for each of the modes. Here is what I have worked out common sense wise. The O and B are the key between cool and heat for the two main modes. The problem is they are jumpered together for the HW TH5000 so I can only assume it has to be a digital signal telling the system which one to use (energize for cool or heat).

    Here is a quick equipment overview:
    HW TH5000 - Current working thermostat - Installation PDFhttp://www.forwardthinking.honeywell.../69_1922es.pdf
    Pro1IAQ T955 - New Thermostat - http://www.pro1iaq.com/resources/ins...anual_t955.pdf
    Air Handler - 4TEC3F42C1000AA

    Does anyone have any suggestions how to fix this?

  2. #2
    Join Date
    Feb 2009
    Location
    Tallahassee, FL
    Posts
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    I do have a suggestion. Its the very first blue highlighted sentence with box around warning in that proiaq manual.

  3. #3
    Join Date
    Jun 2001
    Location
    Moore, Oklahoma, United States
    Posts
    4,136
    We aren't allowed to give DIY advise on this site, the O/B situation may only be part of your problem. In addition to getting the O/B right you will need to set the configuration options correctly or damage to your system may occur.

  4. #4
    Join Date
    Apr 2012
    Location
    winnipeg
    Posts
    1,330
    I concure
    it was working.... played with it.... now its broke.... whats the going hourly rate for HVAC repair

  5. #5
    Quote Originally Posted by 54regcab View Post
    We aren't allowed to give DIY advise on this site, the O/B situation may only be part of your problem. In addition to getting the O/B right you will need to set the configuration options correctly or damage to your system may occur.
    I see I didn't really see changing a thermostat as a DIY thing as it only involves unscrewing terminals and screwing terminals. The system is certainly not damaged as I can reattach the HW thermostat and it works as expected.

    I do find it silly that a "trained experienced technician" is needed. Doing almost anything that requires a manual has some note that says "requires a trained experienced technician". While I wouldn't attempt to replace the entire AC system, changing the thermostat should be pretty basic for the most part. And in fact if the technicians changed the wiring for my AC system to the standard wiring for the new system I do believe this wouldn't be an issue. In fact they used the in place wiring that my previous 20 year old system was using.

    I understand if this is considered DIY type work and this site cannot help.

    Thanks.

  6. #6
    Join Date
    Jul 2006
    Location
    Virginia
    Posts
    4,604
    read up and decide if you need a jumper between o and b ( hint no ) the focuspo 5000 only has 1 o/b terminal and its position is determined in the program ,what brand of unit do you have .
    We really need change now

  7. #7
    Quote Originally Posted by catmanacman View Post
    read up and decide if you need a jumper between o and b ( hint no ) the focuspo 5000 only has 1 o/b terminal and its position is determined in the program ,what brand of unit do you have .
    You're exactly right. apparently the B terminal would be for certain brands that need to energize the heat. My unit does not require this signal. After removing the jumper, everything appears to work well. Heat is coming out well and cool comes out well also.

  8. #8
    Join Date
    May 2009
    Location
    Savannah, Ga/H.H. Island, S.C.
    Posts
    1,394
    Call a professional. You cannot confirm the system is performing/staging without proper testing equipment. This thermostat needs to programmed for these options. Replacing a thermostat is in no way a "basic" procedure for a homeowner.

    You could harm your equipment or yourself.

  9. #9
    Join Date
    Feb 2009
    Location
    Tallahassee, FL
    Posts
    5,975
    It is one of those things we always hear from tradesman.

    Its 98% knowing what those terminal designations are and what they do....as well as what is the best menu setup options.

    2% actually performing the install.

    He could also educate you how using a programmable thermostats and heat pumps with aggressive setbacks can use more strip heat during winter months.

  10. #10
    Join Date
    Dec 2005
    Location
    Cincinnati, Oh
    Posts
    4,884
    Quote Originally Posted by cneal13x View Post
    I see I didn't really see changing a thermostat as a DIY thing as it only involves unscrewing terminals and screwing terminals. The system is certainly not damaged as I can reattach the HW thermostat and it works as expected.

    I do find it silly that a "trained experienced technician" is needed. Doing almost anything that requires a manual has some note that says "requires a trained experienced technician". While I wouldn't attempt to replace the entire AC system, changing the thermostat should be pretty basic for the most part. And in fact if the technicians changed the wiring for my AC system to the standard wiring for the new system I do believe this wouldn't be an issue. In fact they used the in place wiring that my previous 20 year old system was using.

    I understand if this is considered DIY type work and this site cannot help.

    Thanks.
    Are you doing this yourself?

    If so, then it's "doing it yourself", also commonly refered to as "DIY".
    "Better tell the sandman to stay away, because we're gonna be workin on this one all night."

    "Dude, you need more than 2 wires to a condenser to run a 2 stage heatpump."

    "Just get it done son."

    Dad adjusted

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