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Page 19 of 21
Fault Conditions
If the Thermoscreens Heat Pump Warm Air Curtain System does not operate as expected
refer to the fault finding table below:
Symptom
Possible Cause
Action Required
Electrical power is not switched on at
both the Mitsubishi Electric Outdoor
Unit and at the local electrical isolator
next to the Thermoscreens Air Curtain
Switch on power to Mitsubishi
Electric Outdoor Unit and
Thermoscreens Air Curtain
and wait for 30 seconds
BMS Control: Air curtain is set to 'Off'.
Check BMS schedule and
amend if necessary
Manual Control: Manual Room Control,
Fan On/Off switch set to Off '0'
Use Manual Room Control to
adjust fan and heat settings as
appropriate
Air curtain
does not
operate
Problem with air curtain fan motor(s), or
internal wiring, or controls
Use wiring diagram to
investigate possible cause of
fault
Air curtain has been running for less
than 20 minutes and is still warming up
Give system sufficient time to
reach operating condition
BMS Control: Air curtain is set to FAN
(Ambient)
Check BMS schedule and
change to HEAT if necessary
Manual Control: Manual Room Control,
Ambient/Heat switch is set to FAN
(Ambient) ' '
Use Room Control to adjust
fan and heat settings as
appropriate
Fixed Target Temperature on dip switch
SW2 on Mitsubishi interface pcb in air
curtain is set too low for heating
Manual Control: Heat setting switch on
Manual Room Control is set to 'AUTO'
and the SW2 fixed target temperature
has been exceeded
If necessary adjust the fixed
target temperature via dip
switch SW2 (see Page 12)
NB. Air Curtain will only heat if
room air temperature is below
the target temperature.
Air curtain is
discharging
cold air
Air Curtain filters and/or heating coil is
dirty.
Service air curtain as
described in Section –
Servicing on pages 17 & 18
Mitsubishi
Electric
system is
indicating an
error code
A variety of error codes can occur
because of a fault within the air curtain
Refer to Mitsubishi Electric
Service Manual to understand
fault, then inspect and repair
air curtain if there is a fault
If the Heat Pump Warm Air Curtain System is still not operating correctly call for a
Mitsubishi Electric Service Agent.
