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  1. #1

    Fan won't turn off/unit frosting up

    The fan on the outside unit of my approximately 10 year old Carrier heat pump will no longer shut off. It has now been running for 24 hours, and the unit is started to get a fair amount of frost on it. I called for a technician to come take a look but the appointment is not until Thursday (2 days from now). Do I risk damage to the unit if it continues to run? If so, what should I do to avoid damage until the repairman comes?

    Additional info: Recently purchased an older home (ie 4 days ago) with a heat pump. Yesterday, the fan on the outside unit will now not turn off, even if the house is at temperature, the inside fan is not running, or even if the mode is set to ‘OFF’ on the thermostat. Outside air temperature where I am (Pacific NW) is currently high/low of 43/30 F. Could not find any way to shut the unit off directly, and tried flipped all the breakers in the breaker box which oddly did not shut it off either (although there is another box nearby which looks like breakers but is unlabeled. This is not my area...). This is the first heat pump I've ever had so I don't know much about them.

    Thanks in advance for any help.

  2. #2
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,062
    Quote Originally Posted by brownmoses View Post
    The fan on the outside unit of my approximately 10 year old Carrier heat pump will no longer shut off. It has now been running for 24 hours, and the unit is started to get a fair amount of frost on it. I called for a technician to come take a look but the appointment is not until Thursday (2 days from now). Do I risk damage to the unit if it continues to run? If so, what should I do to avoid damage until the repairman comes?

    Additional info: Recently purchased an older home (ie 4 days ago) with a heat pump. Yesterday, the fan on the outside unit will now not turn off, even if the house is at temperature, the inside fan is not running, or even if the mode is set to ‘OFF’ on the thermostat. Outside air temperature where I am (Pacific NW) is currently high/low of 43/30 F. Could not find any way to shut the unit off directly, and tried flipped all the breakers in the breaker box which oddly did not shut it off either (although there is another box nearby which looks like breakers but is unlabeled. This is not my area...). This is the first heat pump I've ever had so I don't know much about them.

    Thanks in advance for any help.
    Well you where on the right track with the circuit breakers, or a disconnect box mounted to the house at the unit.

    Have you tried turning the Tstat off or to emergency heat to see if it stops?

  3. #3
    Quote Originally Posted by second opinion View Post
    Well you where on the right track with the circuit breakers, or a disconnect box mounted to the house at the unit.

    Have you tried turning the Tstat off or to emergency heat to see if it stops?
    Thanks for your reply Second Opinion. No, I have not tried turning off the thermostat or switching it to emergency heat. I will be back at the house in a couple of hours and will try then and post back. I'll look for a box mounted on the house near the unit then as well.

  4. #4
    Quote Originally Posted by second opinion View Post
    Well you where on the right track with the circuit breakers, or a disconnect box mounted to the house at the unit.

    Have you tried turning the Tstat off or to emergency heat to see if it stops?
    OK, so the outside unit continues to run if I switch the mode on the thermostat to emergency heat or to the Off position. When switched to emergency heat the air coming from the registers felt warmer, which as far as I understand is normal (?). On the plus side, switching the thermostat to Cool for a while melted most of the frost so at least I know it won't totally turn to a block of ice.

    As long as I'm not damaging the unit having it run constantly (with or without frost buildup) I'm not overly concerned. I assume the technician will fix it in a couple of days.

  5. #5
    Join Date
    Jun 2011
    Location
    Houston area
    Posts
    1,493
    Hmmm.....turning off all the breakers didn't kill the outside unit? Did you find a small disconnect near the unit? Does your main breaker panel have a main disconnect?
    The picture in my avatar is of the Houston Ship Channel and was taken from my backyard. I like to sit outside and slap mosquitos while watching countless supertankers, barges and cargo ships of every shape and size carry all sorts of deadly toxins to and fro. It's really beautiful at times.....just don't eat the three eyed fish....

    ¯`·.¸¸ .·´¯`· .¸>÷÷(((°>

    `·.¸¸..· ´¯`·.¸ ¸.·´¯` ·.¸>÷÷(((°>

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  6. #6
    Join Date
    Jan 2004
    Location
    PA
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    68,759
    Look to see if there is a disconnect outside at the unit, if so use it to shut the outdoor unit off. If not, then turn off breakers in the other panel box until the outdoor unit shuts off. Running like it is can harm the compressor.

    If you can't find a way to shut it off. Then turn the thermostat's fan switch to on, and leave it run until a tech repairs the current problem.
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  7. #7
    Join Date
    Aug 2000
    Location
    Central Oregon
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    749
    Quote Originally Posted by beenthere View Post
    .
    If you can't find a way to shut it off. Then turn the thermostat's fan switch to on, and leave it run until a tech repairs the current problem.
    Yep keep that fan running if you cant find the breaker.
    If you think our goverment is screwed up. You haven't lived in another country.

  8. #8
    Hi, thanks for the responses. Is this the disconnect? (Not a pic of the actual box but looks close as I remember it. from internet) It is connected to the unit and not to the side of the house, if that matters. Do I just give the metal tab/handle a tug? If it works I assume I just set the thermostat to emergency heat to maintain house temperature then. I will set the fan to 'On' if I can't get it to shut down.

    Not sure if the picture attachment worked. Here is a link as well
    http://wesellac.com/prodimages/disconnectlarge.jpg
    Attached Images Attached Images  

  9. #9
    Join Date
    Aug 2007
    Location
    Northern VA 38 degrees N by 76 degrees W
    Posts
    5,062
    It can be attached to the unit and should look similar.

  10. #10
    Join Date
    Jun 2011
    Location
    Houston area
    Posts
    1,493
    I think we have a winner. That is an equipment disconnect typically used for outside AC units. It should have a piece of grey looking flexible plastic conduit going to your heatpump. Just pull the handle and remove the litlle plastic thingamajig to kill the power to your unit and wait until one those highly sophisticated service techs graces you with his presence.

    If you some reason you cant kill the power, by all means do as the others here have suggested and leave the indoor fan in the "On" position on your thermostat.

    Good luck
    The picture in my avatar is of the Houston Ship Channel and was taken from my backyard. I like to sit outside and slap mosquitos while watching countless supertankers, barges and cargo ships of every shape and size carry all sorts of deadly toxins to and fro. It's really beautiful at times.....just don't eat the three eyed fish....

    ¯`·.¸¸ .·´¯`· .¸>÷÷(((°>

    `·.¸¸..· ´¯`·.¸ ¸.·´¯` ·.¸>÷÷(((°>

    .·´¯`· .¸>÷÷(((°>

    LMAOSHMSFOAIDMT

  11. #11
    Just to close this off in case anyone else runs into this problem: The technician came and had to replace the contactor, which was welded closed, and the defrost switch, which was broken so the defrost cycle wouldn't kick on either. (this is from memory so I might not have the exact name of those parts correct, but you probably know what I'm taling about). It's been a few days now and everything seems to be running correctly.

    Thanks to everyone for their help; it's much appreciated.

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