Modine Manufacturing SSD Installation And Service Manual page 25

TROUBLESHOOTING – INDOOR UNIT
Table 25.1
Troubleshooting – Indoor Unit
TROUBLE
Condensate High Level
(micro units: red alarm LED
will flash at one second
intervals)
Coil Freeze
No Heating (Hot Water)
No Heating (Electric Heat)
POSSIBLE CAUSE
Maximum pump lift exceeded.
Blocked/kinked condensate pipe. See section "Water Leaking From Unit".
Condensate pump blocked or
failed.
Coil freeze up.
Cooling coil freeze protection
thermostat tripped.
(Auto-reset when freeze cleared)
Dirty or blocked air filter.
System head pressure set too
low.
Loss of refrigerant.
Incorrect MODE setting.
(micro units only)
Set point too low.
Blocked or dirty filters causing
low airflow.
No hot water / pumps failed.
Faulty valve / actuator.
Faulty heater relay.
Incorrect MODE setting.
(micro units only)
Set point too low.
Overheat cut out tripped.
(See also section "Electric
Overheat")
Heater element failed.
Faulty heater relay.
POSSIBLE REMEDY
Check that the condensate pump head is no greater than
30". (See page 5 of this manual for installation guide)
See section "Water Leaking From Unit".
A coil freeze condition may have caused excessive
condensate to collect in the drip tray. See section "Coil
Freeze".
Freeze stat is normally closed, opens during freeze.
Where fitted, the stat will disable the cooling action
(sometimes the entire system) during coil freeze
conditions. Use the unit's wiring schematic to investigate.
Clean / replace filters as necessary. (See page 22 for
filter removal and cleaning instructions)
Check condensing pressure, installation of low ambient kit
may be required.
Check system for refrigerant leaks and repair before re-
charging.
Check that the transmitter MODE is set to Heat or Auto
Mode.
Check the set point on the transmitter or wall mounted
thermostat and adjust if necessary.
Check filters condition. (See page 22 for filter removal
and cleaning instructions)
Check hot water source and supply to unit.
Check actuator by manually opening and closing valve,
replace if faulty.
Check signals to relay and check action of relay contacts.
Replace relay or PCB if necessary.
Check that the transmitter MODE is set to Heat or Auto
Mode.
Check the set point on the transmitter or wall mounted
thermostat and adjust if necessary.
Investigate cause of over heat condition.
 Possible low airflow, check filter condition. (See page
22 for filter removal and cleaning instructions)
 Possible fan failure. Check fans.
(See section "Fans Will Not Run")
Remove power from unit and reset manual overheat cut-
out by rubbing. DO NOT PRESS.
Consult Factory for instruction if necessary.
Investigate and replace if necessary.
Check signals to relay and check action of relay contacts.
Replace relay or PCB if necessary.
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