UAB AMALVA we reserve the right to make changes without prior notice.
53
Message
Possible cause
Elimination
Return water temperature
low
Return water temperature of the heater dropped
below the permissible limit.
Check the status and operation of the circulation
pump, heating system and mixing valve actuator.
Internal fire alarm
Fire danger in the ventilation system.
Check the ventilation system. Find the source of
the heat.
External fire alarm
A fire signal has been received from the fire signali
-
zation system of the building.
Delete alarm message and restart the unit when
the fire signal disappears.
External stop
A signal from an external device (switch, timer, or
sensor) has been received.
As soon as the auxiliary device is switched off, the
unit will operate in the previous mode.
Heat exchanger failure
Blocked or not rotating rotor, by-pass damper
failure.
Check the rotor drive, replace the belt or check
the by-pass channel operation.
Heat exchanger icing
Icing may form under a low outdoor temperature
and high room humidity.
Check the operation of the rotation heat ex-
changer drive or the air bypass damper of the
plate heat exchanger.
Low supply air tempera-
ture
The heating equipment fails to operate or its ca-
pacity is insufficient.
Check the heating equipment.
High supply air tempera-
ture
The heating equipment is not controllable (mixing
valve or contactor is blocked).
Check the heating equipment.
Electric heater overheat
The emergency overheating protection of the
electrical heater has actuated.
Protection can be reset only by pressing the RE-
SET press-button on the heater.
Evaporator air tempera-
ture sensor failure
The evaporator air temperature sensor is not con-
nected or broken.
Check connections of the sensor or replace the
sensor.
Evaporator icing
The evaporator is iced over due to excessively
high humidity content in the exhaust air and low
outdoor temperatures.
Check the operation of the evaporator defrost
system.
High pressure on com-
pressor
Compressor system operated in an overload
mode as a result of too high temperature in the
condensing unit.
Indentify the cause and eliminate it.
Low pressure on com-
pressor
Compressor system is leaky or the amount of
refrigerant is insufficient.
Indentify the cause and eliminate it.
Compressor failure
No power supply.
Check supply voltage on the circuit breaker and/or
make sure whether it is on.
Supply voltage mismatches.
Check that the supply voltage is on all three phas-
es, if necessary, swap the two phase conductor
positions.
Compressor motor failure.
Check the compressor motor and replace it if
necessary.
Compressor drive failure.
Check the operation of the compressor drive and
replace it if necessary.
Supply fan drive failure
A fault signal has been received from the supply
fan drive.
Check the supply fan drive and its messages.
Supply fan drive overload The supply fan drive is overloaded.
Check the condition of the supply fan drive and
its cooling.
Supply fan motor failure
The supply fan is broken.
Check the supply fan and replace it if necessary.
Supply fan motor over-
load
The supply fan is overloaded.
Check the condition of the supply fan and make
sure that the resistance of the ventilation system is
not exceeded.
Exhaust fan drive failure
A fault signal has been received from exhaust fan drive. Check the exhaust fan drive and its messages.
Exhaust fan drive over-
load
The exhaust fan drive is overloaded.
Check the condition of the exhaust fan drive and
its cooling.
Exhaust fan motor failure
The exhaust fan is broken.
Check the exhaust fan and replace it if necessary.
Exhaust fan motor over-
load
The exhaust fan is overloaded.
Check the condition of the exhaust fan and make
sure that the resistance of the ventilation system is
not exceeded.
Rotor drive failure
A fault signal has been received from the rotor drive. Check the rotor drive and its messages.
Rotor drive overload
The rotor drive is overloaded.
Check the condition of the rotor drive and its cool-
ing.
