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84-HIGH PRESSURE LOCKOUT 4 HOURS

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traderfjp
traderfjp Member Posts: 15
in A-C, Heat Pumps & Refrigeration
I have an Infinity 96 Heat pump / gas furnace. Temps have been mild here in NC but anyway, I received the 84-HIGH PRESSURE LOCKOUT 4 HOURS message. I checked my coils outside and they were very clean, I changed all my filters which weren't too bad and re-set my system. Not sure what else to check. Is there an indoor coil to clean or a pressure switch to change?
Thanks in advance

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  • HVACNUT
    HVACNUT Member Posts: 5,835
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    In heat mode, the indoor coil becomes the condenser and that is where the high pressure (gas to liquid) exists.

    Things to check are air flow and metering device. TXV or EXV.

    Have you noticed if the defrost cycle is normal?

    Is it one zone or multi zone with the Infinity dampers?
    No blocked vents? Does the air flow seem normal?

    I've only serviced a few of those systems so I'm not too familiar. Is it 4 heat stages? 2 HP and 2 gas?
  • traderfjp
    traderfjp Member Posts: 15
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    HVACNUT said:

    In heat mode, the indoor coil becomes the condenser and that is where the high pressure (gas to liquid) exists.


    The heat pump mostly runs but when there is a huge heat differential or temp go below 35 the propane gas heat turns on. Not sure where the indoor col is. I guess I have to take apart the unit to see.



    Things to check are air flow and metering device. TXV or EXV.




    Not sure what TXV or EXV is but I did do a static air flow test and it was high. 1.03

    Have you noticed if the defrost cycle is normal?




    Not sure how to check this.

    Is it one zone or multi zone with the Infinity dampers?

    No blocked vents? Does the air flow seem normal?




    It's a two stage unit with 3 zones in a 4300 sq. ft house.
    Thanks for helping.
    I've only serviced a few of those systems so I'm not too familiar. Is it 4 heat stages? 2 HP and 2 gas?

  • EBEBRATT-Ed
    EBEBRATT-Ed Member Posts: 15,524
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    The heat coil (evaporator ) is located above the furnace if it's an upflow furnace, next to the furnace on a horizontal unit. Follow the refrigerant lines to the coil. Check the air filter. Make sure the fan runs with nothing blocking the air flow. Were you running heating or cooling when it tripped?
  • traderfjp
    traderfjp Member Posts: 15
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    It was pretty warm here today so not sure if there was a call for heat. It's an upflow. Changed the filters in the main unit and just found the coil. Coil looked pretty clean with some small spots of rust. Fan looks to be unobstructed. Re-started the system about an hour ago and the message is gone for now.
  • traderfjp
    traderfjp Member Posts: 15
    edited April 2020
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    Any chance the problem is a pressure switch that is stuck? Heat pump is on and working as of now and brought room to temp.
  • pecmsg
    pecmsg Member Posts: 4,847
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    1st you need to find out what the actual pressure is. That will tell you if the switch is Bad or Doing its job as designed!

    If it is running high then correct it. Any # of things can cause excessive head pressure in heat mode.
  • HVACNUT
    HVACNUT Member Posts: 5,835
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    If it continues to happen, you'll need a Pro with strong knowledge of the Carrier Infinity system. That's a must as they use communicating controls.
    Your issue could be as simple as a communication error due to a weak signal. Or it could be much much more involved.
  • traderfjp
    traderfjp Member Posts: 15
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    I'll give it a week and see if the problem comes back I'll call a pro. Re-setting the system and putting in new filters seemed to have helped.
  • pecmsg
    pecmsg Member Posts: 4,847
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    traderfjp said:

    I'll give it a week and see if the problem comes back I'll call a pro. Re-setting the system and putting in new filters seemed to have helped.

    Get someone out to investigate and resolve the issue. The switch is doing its job, you need to find out why.
  • unclejohn
    unclejohn Member Posts: 1,833
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    I think 1.03 SP is high. How did you check it, by the Tstat function test. Were the filters dirty when they came out. Any filters in system in ceiling return or wall grills?
  • motoguy128
    motoguy128 Member Posts: 393
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    I used to own one of those systems. In the service screen, it will show the actual system pressures while running and static pressure. 1.03 is very high. Close to max. Surprised you don’t have a warning for that. But unless an airflow alarm is present, you are going ot get airflow, but if the coil is dirty, or filter dryer or outdoor TXV is plugged, you can get highs pressure.

    You probably looked only at the top of the coil. On a upflow furnace you need to slide the coil out or lift it to look Underneith at the side that sees the airflow. Even if you have correct airflow, if the coil is very dirty, it won’t transfer heat. Also if installed wrong, air can bypass the coil.

    Check the fault code history and see how often that’s occurred.
  • pecmsg
    pecmsg Member Posts: 4,847
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    I believe the Infinity does not read actual static but that reading is calculated.

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