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FHP - Flashing Code 2

Article ID: 162
Last updated: 19 Jan, 2017

Florida Heat Pump: EM015

Re: Error Code 2 / Fault Code 2

Code 2 = Low Pressure Switch Fault


Possible Causes (From Most to Least Likely):

  1. Low Refrigerant Charge
  2. Bad Expansion Valve
  3. Low Water Flow (Heating)
  4. Low Airflow (Cooling)
  5. Bad Pressure Switch

CHECKOUT

  1. Check Refrigerant Pressures
    1. Hook-up refrigerant gauges to the system.
    2. Start unit and monitor pressures.
      • Normal R-22 Pressures = 55 - 75 Suction, 200 - 275 Discharge.
      • Normal R410A Pressures = 100 - 150 Suction, 275 - 400 Discharge.
      • Cooling
        • Check Suction Line Temperature --> Calculate Superheat
          • Normal Superheat = 8 to 18 deg.
        • Low Suction + Low Discharge + High Superheat = Low Refrigerant Charge or Bad Expansion Valve
        • Low Suction + Low Discharge + Normal Superheat = Low Air Flow
      • Heating
        • Check water temperature drop at the unit
          • Normal temperature drop = 6 - 12 deg.
        • Low Suction + Low Discharge + High Temp Drop = Low Water Flow
        • Low Suction + Low Discharge + Normal or Low Temp Drop = Low Refrigerant Charge or Bad Expansion Valve
  2. Check Expansion Valve
    • If Low Refrigerant Pressure or Bad Expansion Valve are expected add refrigerant to system.
      • Discharge Pressure Increase & Suction Stays Low or Drops = Bad Expansion Valve
      • Discharge Pressure & Suction Pressure Increase = Good
  3. Check Pressure Switch
    • If refrigerant pressures stays in a normal range but still shows Code 2:
    • Check Pressure Switch
      • Without removing wires, check for 2VAC on both sides of the pressure switch.
        • Power on both sides = Switch Closed (Ok)
        • Power on one side only = Switch Open (Bad Switch)
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Article ID: 162
Last updated: 19 Jan, 2017
Revision: 6
Views: 427
Comments: 0