Table 13 — Troubleshooting
| FAULT | HEATING | COOLING | POSSIBLE CAUSE | SOLUTION | |
Main Power Problems | X | X | Green Status LED Off | Check line voltage circuit breaker and disconnect. | ||
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| Check for line voltage between L1 and L2 on the contactor. | |
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| Check for | |
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| Check primary/secondary voltage on transformer. | |
HP Fault — Code 2 |
| X | Reduced or no water flow in | Check pump operation or valve operation/setting. | ||
High Pressure |
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| cooling | Check water flow adjust to proper flow rate. | ||
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| X | Water temperature out of range | Bring water temperature within design parameters. | |
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| in cooling |
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| X | X | Overcharged with refrigerant | Check superheat/subcooling vs. typical operating condition. | |
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| X | X | Bad HP switch | Check switch continuity and operation. Replace. | |
LP/LOC Fault — Code 3 | X | X | Insufficient charge | Check for refrigerant leaks. | ||
Low Pressure/Loss of |
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| Compressor pump down at | Check charge and | |||
Charge |
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FP1 Fault — Code 4 | X |
| Reduced or no water flow in | Check pump operation or water valve operation/setting. | ||
Source Water Freeze |
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| heating |
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| Plugged strainer or filter. Clean or replace. | ||||
Protection |
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| Check water flow adjust to proper flow rate. | |||
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| X |
| Inadequate antifreeze level | Check antifreeze density with hydrometer. | |
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| X |
| Improper freeze protect setting | Clip JW3 jumper for antifreeze | |
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| Water temperature out of range | Bring water temperature within design parameters. | |
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| X | X | Bad thermistor | Check temperature and impedance correlation. | |
FP2 Fault — Code 5 |
| X | Reduced or no water flow in | Check pump operation or water valve operation/setting. | ||
Load Coil Freeze |
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| heating |
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| Plugged strainer or filter. Clean or replace. | ||||
Protection |
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| Check water flow adjust to proper flow rate. | |||
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| X | Improper freeze protect setting | Clip JW3 jumper for antifreeze | |
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| X | Water temperature out of range | Bring water temperature within design parameters. | |
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| X | X | Bad thermistor | Check temperature and impedance correlation. | |
Over/Under Voltage — | X | X | Under voltage | Check power supply and | ||
Code 7 |
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| Check power supply wire size. | |||
(Auto Resetting) |
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| Check compressor starting. | |||
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| Check | |
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| X | X | Over voltage | Check power supply voltage and | |
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| Check | |
Performance Monitor — | X |
| Heating mode FP2>51.7 C | Check for overcharged unit. | ||
Code 8 |
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| X | Cooling mode FP1>51.7 C OR | Check for poor water flow or airflow. | |||
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| FP2< 4.4 C |
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No Fault Code Shown | X | X | No compressor operation | See scroll compressor rotation section. | ||
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| X | X | Compressor overload | Check and replace if necessary. | |
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| X | X | Control board | Reset power and check operation. | |
Unit Short Cycles | X | X | Unit in Test mode | Reset power or wait 20 minutes for auto exit. | ||
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| X | X | Unit selection | Unit may be oversized for space. Check sizing for actual load of space. | |
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| X | X | Compressor overload | Check and replace if necessary. | |
Unit Does Not Operate in |
| X | Reversing valve | Set for cooling demand and check | ||
Cooling |
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| If RV is stuck, run high pressure up by reducing water flow and while operat- | |||
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| ing engage and disengage RV coil voltage to push valve. | |
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| X | Thermostat setup | Check for ‘O’ RV setup not ‘B’. | |
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| X | Thermostat wiring | Check O wiring at heat pump. Jumper O and R for RV coil. | |
Insufficient Capacity/ | X | X | Low refrigerant charge | Check superheat and subcooling. | ||
Not Cooling or Heating |
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X | X | Restricted metering device | Check superheat and subcooling. Replace. | |||
Properly | ||||||
| X | Defective reversing valve | Perform RV touch test. | |||
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| X | X | Thermostat improperly located | Check location and for air drafts behind thermostat. | |
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| X | X | Unit undersized | Recheck loads and sizing. Check sensible cooling load and heat pump | |
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| capacity. | |
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| X | X | Scaling in water heat exchanger | Perform scaling check and clean if necessary. | |
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| X | X | Inlet water too hot or cold | Check load, loop sizing, loop backfill, ground moisture. | |
High Head Pressure |
| X | Scaling in water heat exchanger | Perform scaling check and clean if necessary. | ||
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| X | X | Unit overcharged | Check superheat and subcooling. Reweigh in charge. | |
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| X | X | Vacuum system and reweigh in charge. | ||
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| X | X | Restricted metering device | Check superheat and subcooling. Replace. | |
Low Suction Pressure | X |
| Reduced water flow in heating | Check pump operation or water valve operation/setting. | ||
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| Plugged strainer or filter. Clean or replace. | |
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| Check water flow adjust to proper flow rate. | |
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| X |
| Water temperature out of range | Bring water temperature within design parameters. | |
| LEGEND |
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FP | — Freeze Protection |
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HP | — High Pressure |
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LED — |
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LOC — Loss of Charge |
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LP | — Low Pressure |
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RV | — Reversing Valve |
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