30
Enertech Global
HP IOM, Rev. B
A: UNIT WILL NOT START IN EITHER CYCLE
Thermostat
Set thermostat on heating and highest temperature setting. Unit should run. Set thermostat on cooling and lowest
temperature setting. Unit should run. Set fan to On position. Fan should run. If unit does not run in any position,
disconnect wires at heat pump terminal block and jump R, G, Y. Unit should run in heating. If unit runs, replace
thermostat with correct thermostat only.
Loose or broken wires
Tighten or replace wires.
Blown Fuse/
Tripped Circuit Breakers
Check fuse size, replace fuse or reset circuit breaker.
Check low voltage circuit breaker.
Low Voltage Circuit
Check 24 volt transformer. If burned out or less than 24 volt, replace. Before replacing, verify tap setting and correct
if necessary�
Water Flow (runs for 30 sec)
If water flow is low (less than 3.5 GPM), unit will not start. Make sure Pump Module or solenoid valve is connected
(see wiring diagram). Water has to flow through the heat exchanger in the right direction (see labels at water fitting
connections) before the compressor can start. If water flow is at normal flow, use an ohmmeter to check if you
get continuity at the flow switch. If no switch is open and flow is a normal flow, remove switch and check for stuck
particles or bad switch.
B: UNIT RUNNING NORMAL, BUT SPACE TEMPERATURE IS UNSTABLE
Thermostat
Thermostat is getting a draft of cold or warm air. Make sure that the wall or hole used to run thermostat wire from
the ceiling or basement is sealed, so no draft can come to the thermostat.
Faulty Thermostat (Replace).
Section 10: Troubleshooting
C: NO WATER FLOW
Pump Module
Make sure Pump Module is connected to the control box relay (check all electrical connections). For non-pressurized
systems, check water level in Pump Module. If full of water, check pump. Close valve on the pump flanges and
loosen pump. Take off pump and see if there is an obstruction in the pump. If pump is defective, replace. For
pressurized systems, check loop pressure. Repressurize if necessary. May require re-flushing if there is air in the
loop�
Solenoid valve
Make sure solenoid valve is connected. Check solenoid. If defective, replace.
D: IN HEATING OR COOLING MODE, UNIT OUTPUT IS LOW
Water
Water flow & temperature insufficient.
Load Side Flow
Check speed setting, check nameplate or data manual for proper speed, and correct speed setting.
Check for dirty air filter—Clean or replace.
Restricted or leaky ductwork. Repair.
Refrigerant charge
Refrigerant charge low, causing inefficient operation. Make adjustments only after airflow and water flow are
checked.
E: IN HEATING OR COOLING MODE, UNIT OUTPUT IS LOW
Water heat exchanger
Check for high-pressure drop, or low temperature drop across the coil. It could be scaled. If scaled, clean with
condenser coil cleaner�
System undersized
Recalculate conditioning load.
F: WATER HEAT EXCHANGER FREEZES IN HEATING MODE
Water flow
Low water flow. Increase flow. See F. No water flow.
Flow Switch
Check switch. If defective, replace.
G: EXCESSIVE HEAD PRESSURE IN HEATING MODE
Load Side Flow
See E: Noisy blower and low air flow.
H: WATER DRIPPING FROM UNIT
Unit not level
Level unit.
Condensation drain line plugged
Unplug condensation line.
Water sucking off the air coil in
cooling mode
Too much airflow. Duct work not completely installed. If duct work is not completely installed, finish duct work.
Check static pressure and compare with air flow chart in spec manual under specific models section. If ductwork is
completely installed it may be necessary to reduce CFM.
Water sucking out of the
drain pan
Install an EZ-Trap or P-Trap on the drain outlet so blower cannot suck air back through the drain outlet.
