Climatemaster Geothermal: TT/TS

Re: Code 2 / High Pressure Fault - Cooling

Code 2 = High Pressure Fault

► There may be (2) Water Pressure Switches wired in series with the refrigerant High Pressure Switch.

► When the high pressure switch opens due to high refrigerant pressures the compressor relay is de-energized immediately since the high pressure switch is in series with the compressor contactor coil.

CHECKOUT:

1. Check Water Pressure

• With the unit off, check the inlet and outlet water pressure (psig).
  • Both pressures should be the same and both should be positive pressure (at least 5psig).

2. Check Loop Pump(s)

• Set the thermostat to call for cooling.
• If the heat pump is in lockout, reset by removing 24VAC power to the control board.
  • Unit goes into High Pressure lockout immediately or as soon as the compressor tries to start = Open Hi Pressure Switch or Open Water Pressure Switch 
• Once the compressor starts, check amperage on each loop pump.
  • Each pump should pull around .7 or .8 amps.
    • Excess amperage = Pump Locked-Up
    • No Amperage = No Power to Pump or Bad Pump
• Re-check the inlet and outlet water pressures.
  • Both pressures should be positive.
  • Record pressure drop.
• Check and Record the inlet water temperature.
• Determine GPM/Ton based on flow chart.
  • Ideal Flow = 3GPM/Ton

3. Check Refrigerant Pressure

• Hook-up refrigerant gauges to the pressure ports on the unit.
  • Blue ⇔ Low Pressure port (typically on the middle line of the reversing valve)
  • Red ⇔ High Pressure port (on the discharge line of the compressor)
• Place an insulated temperature probe on the liquid line between the heat exchanger and expansion valve.
• Ensure that the heat pump is running at full capacity.
• Allow the unit to run for at least 5 minutes.
• Record pressures and temperature as the system operates.
• Record Sub-Cooling
  • Sub-Cooling = Saturation Temp (from the high-pressure gauge) - Liquid Line Temp
• Check and Record water temperature rise.
  • Water Temperature Rise = Outlet Water Temperature - Inlet Water Temperature
• Refer to Performance Chart for normal operating conditions.
  • High Suction Pressure + High Discharge Pressure + Low Sub-Cooling + High Water Temp Rise = Low Water Flow
  • Normal Suction Pressure + High Discharge Pressure + High Sub-Cooling + Normal Water Temp Rise = Refrigerant Over-Charge
  • Low Suction Pressure + High Discharge Pressure + High Sub-Cooling + Low Water Temp Rise = Bad Expansion Valve