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prestige thermostat not starting aux heat

I have a honeywell prestige thermostat with a eqpt interface modual. I have a unico heat pump with a boiler aux heat. when the heat pump fails (or I simulate a failure by powering the outside unit off) the thermostat will just stay status- heat on IE it will stay (lndefinetly) calling for heat pump and does not start the aux heat. I have the installer option set to ' do not let aux heat run with heat pump. and the temp differtial set to 2 degrees. I would expect after trying the heat pump for a short time with no heat increase the aux heat will kick in. it just stay on 'Heat on'

Comments

  • ratio
    ratio Member Posts: 3,173
    Maybe try it with the aux heat permitted to run with the heat pump, to see what it does? I'd be surprised if it bangs on both at the same time.
  • Rich_d
    Rich_d Member Posts: 25
    edited November 2016
    changing that setting does allow the aux heat to come on. However (this is why I changed that setting in the first place) now when the aux heat (hot water coil) comes on the fan will not come on. This is becouse the thermostat has power to green and y1. So the temp sensor on the heat pump coil will never allow the fan to run becouse it is always cold becouse the heat pump is off. So My guess is I need to route the y1 (yellow) through a relay to turn off the power to y1 when aux heat is on. If I disconnect the yellow y1 wire going to the air handler then the fan will run in aux heat.

    sound about right?
  • ratio
    ratio Member Posts: 3,173
    With the thermostat set to heat pump the fan should be energized by the thermostat whenever a heat or cool call is active. You say that the fan comes on if you take the Y1 wire off while an aux heat call is active? I don't know why that might be happening. What is the model number of the heat pump? Which EIM do you have installed? Do you have a dual-fuel kit installed?
  • Rich_d
    Rich_d Member Posts: 25
    With the thermostat set to heat pump the fan should be energized by the thermostat whenever a heat or cool call is active.

    It Is..

    You say that the fan comes on if you take the Y1 wire off while an aux heat call is active?

    correct.

    I don't know why that might be happening.

    I believe it is becouse the heat pump coil is cold so the temp sensor on the heat pum coil is not letting the fan come on.

    What is the model number of the heat pump?

    unico m2430cl1-a

    Which EIM do you have installed?

    sdhv

    Do you have a dual-fuel kit installed?

    no

  • Rich_d
    Rich_d Member Posts: 25
    I thought with the prestige termostat A duel fuel kit would not be necessary, But I can not get it work as expected...
  • ratio
    ratio Member Posts: 3,173
    Does the fan operate correctly when the stat is set to emergency heat?

    Does this match your unit?

    What brought on this problem? New stat? Always been like this? Has something changed?

  • Rich_d
    Rich_d Member Posts: 25
    Does the fan operate correctly when the stat is set to emergency heat?

    yes. in this mode the thermostat does not power up the y1 circut



    match your unit?

    not exactly. it is a I series with a sdhv board which has a mmi board as well as a thermostat relay board.

    What brought on this problem?

    New Install, always been like this. trying to get it corrrect after new install


  • ratio
    ratio Member Posts: 3,173
    Ok, I found this, which is closer to what you have? It indicates that there are three outputs that the iSeries will stage in for aux heating, see page 28. You should be able to use S1 to switch a relay to bring on the hydro coil if the stat doesn't satisfy.

    Another doc I found indicates that the iSeries knows the outdoor temp and will automatcally switch over to hydro heat at an adjustable setpoint, see page 112.

    This system seems pretty sophisticated. I can't seem to find really good docs online, so take what I say with a grain of salt. Have the original installers been unresponsive to your needs?

  • njtommy
    njtommy Member Posts: 1,105
    My question is where does the Ahu get power from? It looked like on most of these units the line voltage gets power from the out door unit. Could that be part of the problem? If your turning off power to the out door unit also not sure where your stat gets power from.
  • Rich_d
    Rich_d Member Posts: 25


    It indicates that there are three outputs that the iSeries will stage in for aux heating, see page 28. You should be able to use S1 to switch a relay to bring on the hydro coil if the stat doesn't satisfy

    correct.



    .

    Another doc I found indicates that the iSeries knows the outdoor temp and will automatcally switch over to hydro heat at an adjustable setpoint,


    correct.


    I Know I can rewire this to work as I need. I am trying to figure out why the thermostat does not work as described.

    This system seems pretty sophisticated.

    yes, the reason the installer went with this particular t-stat is because there is also a venmar system as well that requires the air handler fan to run when it calls. I was told to avoid 3 controls on my wall this was the way to go.

    I can't seem to find really good docs online

    nor can I.


    Have the original installers been unresponsive to your needs?

    They Have been slow to respond then when they do come They do not seem knowledgeable in the system they installed. From my research I now know more about it then they do. Besides I want a full understanding of it as as I usually prefer to fix most issues on my own.... :)

  • Rich_d
    Rich_d Member Posts: 25
    njtommy said:

    My question is where does the Ahu get power from? It looked like on most of these units the line voltage gets power from the out door unit. Could that be part of the problem? If your turning off power to the out door unit also not sure where your stat gets power from.


    They are seperate power sources. the air handler and t-stat definitly have power.
  • ratio
    ratio Member Posts: 3,173
    Again, without this system in front of me, or adequate docs, this is just an educated guess, but...

    It seems to me that the hydro heat is tied in as emergency heat, that means it is working as designed, switching to emergency heat being a manual intervention. Is the hydro heat controlled by the stat, the air handler, or both? If it's operated solely by the stat, then adding a relay to bring on the hydro heat, controlled by S1, should do what you want it to do.

    Try to talk to your installer about your issues. It's nearly always best to go through them, at least until your warranty period is up. I'm quite sure that they want you to be satisfied, even if they are playing catch up with a big bag of mixed controls

  • Rich_d
    Rich_d Member Posts: 25

    >>Again, without this system in front of me, or adequate docs, this is just an educated guess, but... It seems to me that the hydro heat is tied in as emergency heat, that means it is working as designed, switching to emergency heat being a manual intervention. Is the hydro heat controlled by the stat, the air handler, or both?

    Just the T-stat

    >If it's operated solely by the stat, then adding a relay to bring on the hydro heat, controlled by S1, should do what you want it to do.

    correct.




    Try to talk to your installer about your issues. It's nearly always best to go through them, at least until your warranty period is up.

    In full disclosure on that... The wife works for the family business. They are the installers. We got a good deal on the install, So that is why we end up low on the priority list. No worries about the warranties.. :)
  • ratio
    ratio Member Posts: 3,173
    Great, it simplifies things to not have to worry about voiding warranties!

    Near as I can figure, the iSeries and the stat should both be able to command the hydro heat on, the stat for emergency heat, & the iSeries for auxillary heat, both as a second stage and for low ambient HP lockout. It also might be desirable to tie in the hydro as a second stage heat to the stat as well (as opposed to emergency heat), since it's the only thing that knows the room temp & setpoint. Pretty complicated, but it should be doable with enough relays to isolate things safely.

  • Rich_d
    Rich_d Member Posts: 25
    ok... Thanks again for taking the time to help with this..
  • ratio
    ratio Member Posts: 3,173
    NP. Let us know how it works out.