Omega VSHP Series Installation And Operation Manual page 18

OMEGA | WATER SOURCE HEAT PUMPS
Table 7: Troubleshooting Guide
Problem Mode
Heating/Cooling
No response to Heating/Cooling
any thermostat
setting Heating/Cooling
Heating/Cooling
Unit short cycles Heating/Cooling
Heating/Cooling
Heating/Cooling
Heating/Cooling
Only blower runs,
Heating/Cooling
but not compres-
sor
Heating/Cooling
Heating/Cooling
Clogged Drain Pan / Condensate hose /
Heating/Cooling
Heating/Cooling
Heating/Cooling
Loss of conditioned air due to ductwork
Heating/Cooling
Heating/Cooling
Insufficient
capacity
Heating/Cooling
Heating/Cooling
Heating/Cooling
Cooling
Heating/Cooling
Cooling
Cooling
High Pressure
Fault
Heating
Heating
Heating/Cooling
Heating/Cooling
Heating/Cooling
Cooling
Cooling
Cooling
Low Pressure
Fault
Heating
Heating
Heating
Water Loop
Discharge Temp Cooling
Alarm
Water Loop
Supply Temp Heating/Cooling
Alarm
Condensate
Cooling
Overflow Alarm
Heating/Cooling Suction Temperature sensor defective.
Refrigerant
Suction Alarm
Heating/Cooling
15
Possible Cause(s)
Main power off
Defective control transformer
Broken or loose connection
Defective thermostat
Thermostat improperly located
Defective compressor overload
Defective compressor contactor
Supply voltage too low
Defective compressor capacitor
Defective compressor windings
Limit switches open
Faulty Sensor
Dirty filter
Blower RPM too low
leaks
Low on refrigerant charge
Defective reversing valve
Thermostat improperly located
Inadequate water flow
Entering Water Temperature too hot
Entering Water Temperature too cold
Inadequate GPM
Water too hot
Inadequate air flow
Dirty filter
Overcharged with refrigerant
Defective pressure switch
Undercharged
Faulty thermal expansion valve (TXV)
operation
Inadequate air flow
Dirty filter
Inadequate GPM
Inadequate GPM
Inadequate GPM
Inadequate GPM/Too High Riser Loop
Temperature
Too High Riser Loop Temperature
Clogged Drain Pan / Condensate hose
Suction Temperature below threshold
Correction Method
Check unit disconnect switch/ circuit breaker/ fuses
Confirm thermostat is wired correctly before replacing
Check for loose thermostat connections. Repair and/or tighten as required.
Check and replace
Relocate thermostat away from supply registers
Check and replace if required (if external)
Check and replace if required
Correct incoming supply voltage setting at Transformer
Check and replace if required
Check and replace if required
Check for faulty pressure switches. Switches are normally closed. Replace if switches
are open when unit is shutdown.
Condensate switch detects overflow condition in drain pan, check for obstruction. If no
water, check switch, replace if required.
Check and replace
Set to blower to higher fan speed
Check for duct leaks and repair
Possible leak in system. Check for leaks at piping joints and coil. Repair if possible, and
recharge to unit nameplate charge rating.
Check and replace
Relocate thermostat
Increase GPM
Adjust EWT Loop temperature lower
Adjust EWT Loop temperature higher
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.
Reduce water loop temperature
Check blower. Typical airflow should be 400 cfm/Ton across air coil. Check for dirty or
obstructed air coil.
Clean/replace
Decrease charge/Confirm charge matches nameplate.
Check or replace
Possible leak in system. Check for leaks at piping joints and coil. Repair if possible, and
recharge to unit nameplate charge rating.
Flooding of refrigerant caused by the TX valve not opening/closing correctly. Check TX
valve bulb has not come loose.
Check blower. Typical airflow should be 400 cfm/Ton across air coil. Check for dirty or
obstructed air coil
Check and replace
Check GPM to unit. If auto-flow reg. valve installed check GPM matches rating of auto-
flow reg. valve.
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.
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.
Leaving water temperature from water coil exceeds acceptable operating temperature
o
(127 F). Check for clogged or faulty water components, or too low GPM riser supply or
too high entering water temperature.
Entering water temperature to water coil exceeds acceptable operating temperature
o
(115 F). Lower riser water loop temperature.
Condensate switch detects overflow condition in cabinet drain pan. Check for plugged,
obstructed or pinched condensate hose.
Check that sensor is not open or closed. Check for resistance, if reading Zero of Infinity
replace sensor.
o
Suction temperature is below 50 F in cooling and 70
causes under "Low Pressure Fault".
OMEGA-VSHP.F-IOM-1907
o
F in heating. Refer to possible
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