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  1. #27
    Join Date
    Dec 2002
    Location
    Rochester, MN
    Posts
    5,305
    I agree w/ Tpa fl,

    Upgrade to a true Vision Pro if you have two stage heating and cooling system.

    Home Depot don't sell this style.. Just the very basic vision w/ buttons. I am suprise how well they are selling.

  2. #28
    Join Date
    Apr 2005
    Posts
    13
    Originally posted by tpa-fl
    Looking through the manual... that's definitely *not* the same stat as the VisionPRO series. A cursory glance at the manuals shows that the remote sensors (indoor & outdoor) are missing on the 8500, the software's definitely different, and the stat isn't able to use the 24vAC to power itself & the backlight. The 8500 appears to only be capable of single stage cooling with a heat pump, and you've indicated that you have a multi-stage Trane. Not sure if you were referring to just heat or both heating & cooling. If the latter, you absolutely need a different thermostat to get both stages of cooling to work properly.

    Difficult to say what other shortcuts Honeywell took, but I wouldn't be surprised if there were some physical differences that were employed to save costs as well.

    Software-wise, the 8500 stat has almost nothing adjustable compared to the true VisionPRO series. Even the key sequence to get into the installer mode are different. The 8500 also lacks the fan circulation mode, auto changeover, limits, compressor lock-out based on outside temperature, heat stage selection based on outside temperature, and probably quite a few other things that I've not even used yet. If it were me, I'd call up a pro and have them install the pro version. It sounds like Honeywell went cheap to get their DIY stat on the shelf and left out some rather useful things in the process. I can understand why they left out some of the options, as an unknowing homeowner could really screw up their system in choosing the wrong options, but still...they've done more than just neuter the VisionPRO stats to make the RTH8500.
    You are very correct, this is the retail version, not the trade version. It is callled " Vision " , but the " VisionPRO" is a trade only product for professionals. The version in question will do upto 2H/2C but lacks alot of the other tweaks fo the PRO version.

    I dont think that Honeywell went cheap with this product, but rather tried to seperate the professional grade and the retail grade. This is common upon larger manufacturers.

  3. #29
    Join Date
    Apr 2005
    Location
    Tampa, Florida
    Posts
    1,634
    Take a closer look at it. The Vision(non-pro) won't do 2H/2C with a heat pump though, while the VisionPro offers a 2H/2C HP & 3H/2C HP modes. There have to be some physical differences, as it sounds like the non-pro stat also requires batteries to function, whereas the Pro stat is quite happy to run on 24vAC sans batteries. Also, I didn't see any provision for an outside sensor, so how does the non-Pro stat determine when it's time to give up on the HP and go to the aux. heat?

    If anything, I think Honeywell's doing the contractors (and themselves) a disservice by selling a <I>similar-looking</I> but a lesser-feature (and probably lesser quality) stat in the retail stores. The consumers will automatically assume that if it looks the same, it is the same. I'd have to wonder how most homeowners would handle changing out a heat pump stat.. Give 'em a Trane HP, and watch the transformer smoke when they try to hook up the Trane common (B) to the stat's B terminal. Guess the end result is more work for the pros.

  4. #30
    Join Date
    Apr 2005
    Posts
    83
    Thanks for all the advice, I have found a vision pro on ebay and will probably get it.

    Is this one very hard to hook up?

    I currently have 5 wires on my tstat.

    Thanks,
    Felix

  5. #31
    Join Date
    Apr 2005
    Posts
    83
    Thanks for all the advice, I have found a vision pro on ebay and will probably get it.

    http://cgi.ebay.com/ws/eBayISAPI.dll...sPageName=WDVW

    I have 2 heat 1 cool, would this one be ok?

    Is this one very hard to hook up?

    I currently have 5 wires on my tstat.

    Thanks,
    Felix

  6. #32
    Join Date
    Apr 2005
    Posts
    13
    That will work perfect. The wiring diagram is very easy to understand.

  7. #33
    Join Date
    Apr 2005
    Posts
    83
    Thank you Giono!

    I just want to make sure with my wiring before I pluck down another $100

    My current cofig:
    Red wire on R
    Orange on O
    Yellow on Y
    Green on G
    Blue on C
    White (Was w2) TO AUX & E jumped

    Can someone let me know what the setup would be for the new visionpro??

    Thank a great deal to all,

    Felix

  8. #34
    Join Date
    Apr 2005
    Posts
    83
    Anybody on my above post?

    Felix

  9. #35
    Join Date
    Jun 2003
    Location
    Florida
    Posts
    9,548
    You'll get the same manual as I was refering to with the VisionPro. Didn't know you were using a Vision....You would have been better off having a pro install this for you. If you buy it off of Ebay, they probably won't warranty it unless it's professionally installed.It's also electronic, which means they'll probably blame you if it doesn't work(installed improperly....no refund). If you insist on doing this yourself, you're wiring looks fine as long as you follow the instructions provided, as we're not allowed to give you step by step installation instructions here. Good luck.
    If everything was always done "by the book"....the book would never change.

  10. #36
    Join Date
    Apr 2005
    Posts
    83
    Thanks smokin!

    So I called HW and this is what they told me:


    According to HW the cycle rate is 3 for the a/c with a heat pump system, but the a/c can cycle more based on load conditions. Is this correct?

    She said that it has a +/- 1-degree range and she said that once it hits – 1 degree it will turn on and she said this is a ok. Am I missing something?

    Is the cycle rate the amount of times my AC clicks on?


    Felix



  11. #37
    Join Date
    Apr 2005
    Location
    Tampa, Florida
    Posts
    1,634
    You said you have a multi-stage HP? (and I'm assuming it's suppsoed to be multi-stage for both heating AND cooling) BUT, you only have 5 wires? Either you have multi-stage cooling and it's wired so that the second stage engages after a certain amount of time (in which case, you'd want it to be re-wired so that the thermostat would control this for best energy efficiency and comfort) or the system really only has single stage cooling. When in doubt, call a pro... If you connect it up wrong, you can easily blow out the transformer inside the AC and watch your new thermostat go up in smoke. In the worst cases, you can damage the circuit boards inside the air handler and compressor, all which will cost far more to fix than having a pro install the thermostat properly. It has been posted elsewhere in here, but the Honeywell 5 year warranty is VOID if the stat was purchased from E-Bay.

    On the VisionPro thermostats, the cycles per hour is installer-configured, with the choices being anywhere from 1-6 cycles per hour for cooling, 1-12 cycles per hour for heating. As far as how often the AC runs, Honeywell's gotten rather creative with this thermostat and it runs mathematical equations to maintain the temperature as close as possible given the cycles per hour chosen.

    Here's how Honeywell describes it from the thermostat manual:

    P+I Control
    The thermostat microprocessor-based control requires that
    the user understands temperature control and thermostat
    performance. A conventional mechanical or electronic
    thermostat does not control temperature precisely at setpoint.
    Typically there is an offset (droop) in the control point as the
    system load changes. This is a phenomenon that most people
    in the industry know and accept. Many factors contribute to
    offset including switch differential, thermal lag, overshoot,
    cycle rates and system load.
    The thermostat microprocessor simultaneously gathers,
    compares and computes data. Using this data, it controls a
    wide variety of functions. The special proprietary algorithm
    (program) in the thermostat eliminates the factors causing
    offset. This makes temperature control more accurate than
    the conventional mechanical or electronic thermostats. The
    temperature control algorithm is called proportional plus
    integral (P+I) control.
    The thermostat sensor, located on the thermostat or remote,
    senses the current space temperature. The proportional error
    is calculated by comparing the sensed temperature to the
    programmed setpoint. The deviation from the setpoint is the
    proportional error.
    The thermostat also determines integral error, which is a
    deviation based on the length of error time. The sum of the
    two errors is the (P+I) error. The cycle rate used to reach and
    maintain the setpoint temperature is computed using the P+I.
    The additon of the integral error is what differentiates the
    thermostat from many other electronic and mechanical
    thermostats.

    [Edited by tpa-fl on 04-18-2005 at 12:40 PM]

  12. #38
    Join Date
    Apr 2005
    Posts
    83
    TPA-Fl:

    The unit in my garage states Heat 2 stages, cool 1 stage so I guess I only have one stage of cool. Based on this would yoyu same I'm wired ok?

    The Tstat has been wire since Jan with no problems if it were wired wrong would something have burnt out by this point?



  13. #39
    Join Date
    Apr 2005
    Posts
    83
    With all of this said I guess my main concern is my AC unit.

    From all of what I wrote, and with my unit cycling about 5 times an hour do you all think my A/C will be ok or should I switch back to my old analog Tstat to avoind damaging my unit? I am only asking for opinions as I am at a total loss.

    Thank you all once again fro your help & input,
    Felix

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