Table 29 — 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 24 vac between R and C on controller. |
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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 |
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| Check water flow adjust to proper flow rate. | ||
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| X | Water temperature out of | Bring water temperature within design parameters. |
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| range in cooling |
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| X |
| Reduced or no airflow in heat- | Check for dirty air filter and clean or replace. |
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| ing | Check fan motor operation and airflow restrictions. |
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| Dirty air coil — construction dust etc. |
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| External static too high. Check Tables |
| X |
| Air temperature out of range in | Bring |
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| heating |
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| X | X | Overcharged with refrigerant | Check superheat/subcooling vs typical operating condition Tables |
| 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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X |
| 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. |
Water Freeze Protection |
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| heating |
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| Plugged strainer or filter. Clean or replace. | ||
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| Check water flow adjust to proper flow rate. |
| X |
| Inadequate antifreeze level | Check antifreeze density with hydrometer. |
| X |
| Improper freeze protect set- | Clip JW2 jumper for antifreeze (10 F) use. |
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| ting (30 F vs 10 F) |
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| X |
| Water temperature out of | Bring water temperature within design parameters. |
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| range |
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| X | X | Bad thermistor | Check temperature and impedance correlation. |
FP2 Fault — Code 5 |
| X | Reduced or no airflow in cool- | Check for dirty air filter and clean or replace. |
Air Coil Freeze |
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| ing |
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| Check fan motor operation and airflow restrictions. | ||
Protection |
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| External static too high. Check Tables | |
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| X | Air temperature out of range | Too much cold vent air. Bring |
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| parameters. |
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| X | Improper freeze protect set- | Normal airside applications will require 30 F only. |
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| ting (30 F vs 10 F) |
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| X | X | Bad thermistor | Check temperature and impedance correlation. |
Condensate Fault — | X | X | Blocked drain | Check for blockage and clean drain. |
Code 6 | X | X | Improper trap | Check trap dimensions and location ahead of vent. |
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| X | Poor drainage | Check for piping slope away from unit. |
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| Check slope of unit toward outlet. |
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| Poor venting. Check vent location. |
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| X | Moisture on sensor | Check for moisture shorting to air coil. |
Over/Under Voltage — | X | X | Under voltage | Check power supply and 24 vac voltage before and during operation. |
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 24 vac and unit transformer tap for correct power supply voltage. |
| X | X | Over voltage | Check power supply voltage and 24 vac before and during operation. |
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| Check 24 vac and unit transformer tap for correct power supply voltage. |
Performance Monitor — | X |
| Heating mode FP2>125 F | Check for poor airflow or overcharged unit. |
Code 8 |
| X | Cooling mode FP1>125 F OR | Check for poor water flow or airflow. |
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| FP2< 40 F |
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FP1 and FP2 | X |
| FP1 temperature is higher | Swap FP1 and FP2 thermistors. |
Thermistors — |
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| than FP2 temperature. |
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Code 9 |
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| X | FP2 temperature is higher | Swap FP1 and FP2 thermistors. | |
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| than FP1 temperature. |
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No Fault Code Shown | X | X | No compressor operation | See scroll compressor rotation section on page 28. |
| X | X | Compressor overload | Check and replace if necessary. |
| X | X | Control board | Reset power and check operation. |
Unit Short Cycles | X | X | Dirty air filter | Check and clean air filter. |
| X | X | Unit in 'Test Mode' | Reset power or wait 20 minutes for auto exit. |
| X | X | Unit selection | Unit may be oversized for space. Check sizing for actual load of space. |
| X | X | Compressor overload | Check and replace if necessary. |
Only Fan Runs | X | X | Thermostat position | Ensure thermostat set for heating or cooling operation. |
| X | X | Unit locked out | Check for lockout codes. Reset power. |
| X | X | Compressor overload | Check compressor overload. Replace if necessary. |
| X | X | Thermostat wiring | Check Y and W wiring at heat pump. Jumper Y and R for compressor |
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| operation in Test mode. |
LEGEND |
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RV — Reversing Valve |
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