Mitsubishi Heavy Industries FDCW100VNX, Technical Manual

Page: 113 / 173

Service
- 112 -
7 - Anti freeze HX
If the phenomenon persists,
If the phenomenon persists,
Replace the indoor unit relay board AA6.
Replace the pump.
Bleed the air in the water line.
Clean - up the strainer.
Replace the valve(s).
Replace the indoor unit relay board AA6.
Is air - bleed done properly?
Is the operation signal of the
valves outputted correctly?
Is the valve(s) (QM31 or QN11)
functioning properly?
Is there clogging on the strainer
on the water line?
Is the circulation pump setting
(2.2.5) done properly?
Is the min supply cooling setting
(2.2.4) too low?
Set the value higher so as not
to affect the room comfort.
Set the appropriate value
to obtain enough water flow.
Is the operation signal
of the pump outputted correctly?
If the phenomena persists,
Recharge the refrigerant.
Replace the LP sensor.
Plug in the connector surely.
Is the low pressure sensor
on the outdoor unit corrected
properly?
Open it.
Open it.
Does the low pressure saturated temperature
correspond to the liquid line temperature (BT15)?
Is the valve of the refrigeration
circuit on the outdoor unit open?
Is the charged refrigerant
amount correct?
Is the service valve on the
water line open?
YES
YES
YES
YES
YES
YES
YES
NO
NO
YES
YES
NO
NO
NO
NO
NO
YES
YES
YES
NO
NO
NO
NO
NO
Troubleshooting guide