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  1. #1
    Join Date
    Sep 2002
    Posts
    511
    I am new to heat pumps.

    I went to check a heatpump today with outdoor ambient at 68°,in the heat mode the discharge gas went thru the reversing valve to the indoor coil and was putting heat out at the registers.
    The suction gauge was pegged out and the high side gauge was around 70psig.
    when I switched to cool mode,something strange happened,the compressor acted like it was trying to start and after a couple of tries it started up.
    These are the readings:M#CPH481FB S#9601075257
    135psig high side
    75psig low side
    8.80 amps
    9.16 amps
    194° discharge temp
    71.9°suction line temp / superheat:27°
    70.4 liquid line temp / subcooling:6.4°

    Low Charge

    I went into the attic and checked coil and airflow,the coil was descent clean and airflow was good.
    I inspected line set and coil for leaks and found none.
    I will have to go back with D-tek and check further.
    Oh,yeah and a large fire ant mound around the compressor,I was only able to dig out part of it today.
    Any suggestions? thanks



    [Edited by cobitech on 02-16-2005 at 08:28 PM]

  2. #2
    Join Date
    Nov 2001
    Posts
    1,874
    Just acouple things,

    68* is to warm to be running in the heat mode for long.

    You must not have had your gauges on the correct ports to be getting 135 psi on the high side. I don't know any heat pump that would do 194* supply temp. You'd tripping high side safties.
    Also you don't put the temp probe in the plenum.

    I would go over the unit again in the cooling mode, If it's another warm day. Block some of the condenser off, the raise the head pressure to about 225. Let it run to stabilze. then check your line temps and SH & SC which ever is recommened by the MFG.

    Don't bounce back and forth from heat to cool on a warm day.
    If you try to fail, and succeed.
    Which have you done ?



  3. #3
    Join Date
    Nov 2004
    Location
    South Carolina
    Posts
    9
    Here in South Carolina there are alot of heat pumps and for the life of me I have no clue why your giving 2 different amp readings on I assume the compressor. Heat pumps to be correctly charged need the charge weighed in per manufactors data plate since your new to heat pumps. Were your pressure readings in the cool mode? You do not list indoor temp. And I hate to assume stuff.

  4. #4
    Join Date
    Sep 2002
    Posts
    511
    The pressure reading where in the cool mode and the indoor ambient was 74°.
    The Amp reading was taken off the contactor wiring going to the compressor.
    194°was discharge line temp.

    [Edited by cobitech on 02-16-2005 at 11:29 PM]

  5. #5

    If

    If you had the gauges on the Hi and low ports at the service valves and was in the heat mode with the low side calling you a retard(its on the gage) and the high side at 70 psig you got a problem with the Piston or txv (dought if the goodman got a TXv on the indoor coil). And if you switched from heat to cool without letting the pressures equilize no wonder the compressor had a hard time starting.
    On cooling with 75 on the suction and 135 on the liquid,low charge would be my last ideal.

  6. #6
    Join Date
    Sep 2002
    Posts
    511
    The bottom rows of the A-coil where freezing up pretty good by the time I got to the attic to check the air handler side.

    And I didn't let the pressure equalize which is probably the reason why the compressor had a hard time starting.

    I did test this unit initially in the heat mode and then switched it to the cool mode for the rest of the time I was there.

    I could hear the refrigerant gurgling through the refrigerant lines in the attic while I was looking for the leak.

    I think that I am looking at a low charge situation.

  7. #7
    Join Date
    Jan 2005
    Posts
    96
    cobitech,your going to trash your suction gauge unless you connect directly to compressor port when in heat mode.

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