41
Table 29 — Troubleshooting
FAULT
COOLING
HEATING
CHECK
POSSIBLE CAUSE
SOLUTION
No Compressor
Operation but Fan Runs
X
Is fault LED Blinking
1 time?
High Pressure fault - no or low
water flow
Check water valves and/or pumps for proper opera-
tion. Check for water coil blockage.
High Pressure fault - high
water temperature
Check water temperature - is it in range?
High Pressure fault - fouled or
scaled water coil
Check for proper flow rate and water temperature, but
low water side temp rise in cooling.
X
High Pressure fault - no or low
airflow
Check fan motor for proper operation.
Check air filter.
Inspect air coil for dirt/debris.
Check ductwork - are dampers closed or blocked?
X
Is fault LED Blinking
2 times?
Low Pressure fault - no or low
airflow
Check fan motor for proper operation.
Check air filter
Inspect air coil for dirt/debris
Check ductwork - are dampers closed or blocked?
Low Pressure fault - low refrig-
erant
Check refrigerant pressure with gage set
X
Low Pressure fault - no or low
water flow
Check water valves and/or pumps for proper opera-
tion. Check for water coil blockage.
Low Pressure fault - low refrig-
erant
Check for proper flow rate and water temperature, but
low water side temp drop in heating.
X
Is fault LED Blinking
3 times?
Freeze fault, water coil - no or
low water flow
Check water valves and/or pumps for proper opera-
tion. Check for water coil blockage.
Freeze fault - low water tem-
perature
Check water temperature - is it below 40°F entering?
If heat pump is connected to a closed loop with anti-
freeze check that the " FREEZE 1" resistor on the
Complete C board has been cut to set the unit to anti-
freeze mode.
Freeze fault - low refrigerant
Check refrigerant pressure with gage set
X
Is fault LED
Blinking
4 times?
Condensate fault - poor drain-
age
Check condensate pan for high water level. Check
drain line for blockages, double trapping or inadequate
trapping.
Condensate fault - blocked
return air
Check condensate pan for high water level. Check air
filter and return air ductwork for blockage. Check that
there is adequate space between the return air open-
ing and walls or other obstructions on free return
applications.
X
X
Is fault LED Blinking
5 times?
Brown out fault - low
supply voltage
Check primary voltage - ensure it is within the limits
listed on the unit data plate.
Brown out fault -
overloaded control
circuit
Check control voltage - if it is below 18 V check acces-
sories connected to the unit and insure that they do
not exceed the VA draw shown on page 21.
Brown out fault - bad
thermostat connection
Check that thermostat wiring is proper gage and
length, that it is not damaged and that all connections
at the thermostat and heat pump are secure.
X
Is fault LED Blinking
6 times?
Freeze fault, air coil - no or low
airflow
Check fan motor for proper operation.
Check air filter
Inspect air coil for dirt/debris
Check ductwork - are dampers closed or blocked?
Freeze fault, air coil - blocked
return air
Check that there is adequate space between the
return air opening and walls or other obstructions on
free return applications.
Freeze fault, air coil - low
refrigerant
Check refrigerant pressure with gage set.
X
X
No fault LED -
contactor not
energized
Thermostat not calling for
compressor operation
Ensure that the thermostat is on and calling for " Y" .
Bad thermostat connection
Check " Y" connection from thermostat. Ensure that
there is 24 VAC between " Y" and " C" .
Loose wire to contactor coil
Check wiring - insure that there is 24 VAC across the
contactor coil.
Burned out contactor coil
Test contactor with 24VAC (between " R" and " C" ).
Ohm contactor coil - an open circuit indicates a
burned coil.
X
X
No fault LED -
contactor energized
Open compressor
overload
Check for supply voltage at the load side of the con-
tactor. For 3 phase models check phase rotation and
voltage at all 3 phases.
Poor wiring connections
Look for signs of heat on the wiring insulation. Check
that all wiring connections are secure and properly
torqued.
Burned out compressor
Does compressor hum when power is applied? If not
check the resistance of the compressor windings
using the values shown in the compressor character-
istics chart. Note that the compressor must be cool
(70°F) when checking the windings.