Illinois Please advise

Discussion in 'General Discussions' started by mike smith, Jun 12, 2017.

  1. mike smith

    mike smith New Member

    I have 5 series Water Furnace system. 2 years old. Turned on cooling several weeks ago. Outside temps in 90F range. Thermostat set at 73F. Have 2 zones active. 6 ton unit.

    The blower runs 23 hrs/day, literally. Much of the time the unit in standby mode, with fan on speed #3. When the temp rises, the unit goes directly to cooling stage 2, cools down, then shuts down for a few minutes. Then fan comes on at low speed and stays on all the time.

    Tried turning dehumidifier on and off, but that did not make much difference. Also, the unit is connected to ERV in the attic.

    1. Why is fan on so much? It does not take much energy at all, but is that bad? Will it wear out fast?
    2. Why does it use stage 2 cooling so much? I set the differentials to 0.5 degrees for stage 1 and 2 degrees for stage 2. It simply lets the temp in the room go up 2 degrees and then goes directly to stage 2. Then it stays in stage 2 until temps come down almost all the way. I do not remember this happening last year. Heating also was not an issue. Even with subzero temps, stage 2 was rarely used.

    Thanks very much.
    Last edited: Jun 12, 2017
  2. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    2 zones means a zone board. It determines stage 1 or 2.

    Look closely at the thermostats - one maybe set for fan "on" vs fan "auto"

    It is also possible that the ERV installer decided continuous fan operation is needed for that to work right.
  3. geoxne

    geoxne Active Member Forum Leader

  4. mike smith

    mike smith New Member

    Thank you. That makes sense now.

    One other question.

    Happened several times last year and once now, both times during the summer. The technician was here a few days before to check everything. He added "half a glass" of water to the loop. No errors. The unit was up cooling since May without any errors.

    A day after the technician was here, I had E4 error code (Freeze error FP2), same as last year. Unit locked out in the middle of the night. Any ideas what could have caused it? I hit reset and it went on working, but not sure why. By the way, I have a second identical unit that never had this issue.

    Thanks again.
  5. engineer

    engineer Well-Known Member Industry Professional Forum Leader

    I hope the system has PT ports so that a competent technician can measure and calculate heat of rejection (HR) in cooling mode.
    The result of that exercise may lead to an investigation of the system's refrigerant circuit. If HR is well short of spec, there may be a loss of charge (refrigerant leak) or metering device problem.

    Earlier posts suggest possibility system compressor may not be operating at all in low stage. Much depends on the competence of the tech whose boots are on the ground.

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