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.
| Qty |
Possible Causes: |
|
Refrigerant Over-Charge |
|
Bad Expansion Valve |
| 3 |
Low Water Pressure |
| 1 |
Low Water Flow |
|
Bad Pressure Switch |
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.
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