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OMEGA | WATER SOURCE HEAT PUMPS
OMEGA-VSHP.G-IOM-2103
15
Table 7: Troubleshooting Guide
Problem
Mode
Possible Cause(s)
Correction Method
Heating/Cooling
Main power off
Check unit disconnect switch/ circuit breaker/ fuses
Heating/Cooling
Defective control transformer
Confirm thermostat is wired correctly before replacing
Heating/Cooling
Broken or loose connection
Check for loose thermostat connections. Repair and/or tighten as required.
Heating/Cooling
Defective thermostat
Check and replace
Unit short cycles
Heating/Cooling
Thermostat improperly located
Relocate thermostat away from supply registers
Heating/Cooling
Defective compressor overload
Check and replace if required (if external)
Heating/Cooling
Defective compressor contactor
Check and replace if required
Heating/Cooling
Supply voltage too low
Correct incoming supply voltage setting at Transformer
Heating/Cooling
Defective compressor capacitor
Check and replace if required
Heating/Cooling
Defective compressor windings
Check and replace if required
Heating/Cooling
Limit switches open
Check for faulty pressure switches. Switches are normally closed. Replace if switches are open
when unit is shutdown.
Heating/Cooling
Clogged Drain Pan / Condensate hose /
Faulty Sensor
Condensate switch detects overflow condition in drain pan, check for obstruction. If no water,
check switch, replace if required.
Heating/Cooling
Dirty filter
Check and replace
Heating/Cooling
Blower RPM too low
Set to blower to higher fan speed
Heating/Cooling
Loss of conditioned air due to ductwork
leaks
Check for duct leaks and repair
Heating/Cooling
Low on refrigerant charge
Possible leak in system. Check for leaks at piping joints and coil. Repair if possible, and
recharge to unit nameplate charge rating.
Heating/Cooling
Defective reversing valve
Check and replace
Heating/Cooling
Thermostat improperly located
Relocate thermostat
Heating/Cooling
Inadequate water flow
Increase GPM
Cooling
Entering Water Temperature too hot
Adjust EWT Loop temperature lower
Heating/Cooling
Entering Water Temperature too cold
Adjust EWT Loop temperature higher
Cooling
Inadequate GPM
If auto shut-off valve is installed, check that control valve actuator opens during call for Heating.
Set valve to manual mode and remove power connections from actuator and re-test. If manual
mode re-test confirms proper water flow, actuator is likely faulty.
Cooling
Water too hot
Reduce water loop temperature
Heating
Inadequate air flow
Check blower. Typical airflow should be 400 cfm/Ton across air coil. Check for dirty or
obstructed air coil.
Heating
Dirty filter
Clean/replace
Heating/Cooling
Overcharged with refrigerant
Decrease charge/Confirm charge matches nameplate.
Heating/Cooling
Defective pressure switch
Check connections. Jumper terminals and check that it is not a control board issue. Replace if
switch remains open.
Heating/Cooling
Undercharged
Possible leak in system. Check for leaks at piping joints and coil. Repair if possible, and
recharge to unit nameplate charge rating.
Cooling
Faulty thermal expansion valve (TXV)
operation
Flooding of refrigerant caused by the TX valve not opening/closing correctly. Check TX valve
bulb has not come loose.
Cooling
Inadequate air flow
Check blower. Typical airflow should be 400 cfm/Ton across air coil. Check for dirty or
obstructed air coil
Cooling
Dirty filter
Check and replace
Heating
Inadequate GPM
Check GPM to unit. If auto-flow reg. valve installed check GPM matches rating of auto-flow reg.
valve.
Heating
Inadequate GPM
If auto shut-off valve is installed, check that control valve actuator opens during call for Heating.
Set valve to manual mode and remove power connections from actuator and re-test. If manual
mode re-test confirms proper water flow, actuator is likely faulty.
Heating
Inadequate GPM
Inadequate water flow from riser loop system. Units are nominally rated for 3GPM/Ton. Check
water flow from riser system and confirm capability to provide required GPM to unit.
Water Loop
Discharge Temp
Alarm
Cooling
Inadequate GPM/Too High Riser Loop
Temperature
Leaving water temperature from water coil exceeds acceptable operating temperature (127
o
F).
Check for clogged or faulty water components, or too low GPM riser supply or too high entering
water temperature.
Water Loop
Supply Temp
Alarm
Heating/Cooling
Too High Riser Loop Temperature
Entering water temperature to water coil exceeds acceptable operating temperature (115
o
F).
Lower riser water loop temperature.
Condensate
Overflow Alarm
Cooling
Clogged Drain Pan / Condensate hose
Condensate switch detects overflow condition in cabinet drain pan. Check connections. Check
for plugged, obstructed or pinched condensate hose.
Heating/Cooling
Suction Temperature sensor defective.
Check connections. Check sensor is not shorted or stuck in open circuit. Check for resistance, if
reading Zero or Infinity replace sensor.
Heating/Cooling
Suction Temperature below threshold
Suction temperature is below 50
o
F in cooling and 70
o
F in heating. Refer to possible causes
under "Low Pressure Fault".
Refrigerant
Suction Alarm
No response to
any thermostat
setting
Insufficient
capacity
High Pressure
Fault
Low Pressure
Fault
Only blower runs,
but not
compressor