Fujitsu WATERSTAGE 112 Maintenance Document page 60

Heat Pump, Split System, Single Service, 3 phase
5.1.3 Refrigeration System
Unit produces no heat
The unit remains in continuous scanning mode.
Initial checks:
Check the settings
Are the data sent by the user interface received by the heat pump?
60
Hydraulic unit
No
electronic circuit
sending data to
outdoor unit ?
Yes
No
Compressor
running ?
Yes
No
Operating pressure
OK ?
Yes
No
4-way valve
switching ?
Yes
No
Expansion correct ?
expansion valve
Yes
Inspect refrigeration
lines (clogging)
Hydraulic unit electronic system faulty
Inspect PCB
Charge to balance
Problem solved?
No
Valve coil faulty ?
Change
No
Change 4-way valve
after testing
Yes
Servicing complete
Yes
Change coil
Maintenance Document 1394-1