Mitsubishi Electric CMB-WM108V-AA Service Handbook page 200

[ VIII Troubleshooting ]
3. Troubleshooting flow chart for LEV, Solenoid valve, and Valve block
(1) LEV
No cooling capacity
No heating capacity
Check whether the electric expansion
valve and the solenoid valve connector
are not disconnected or not loose.
Fault is found.
Run the cooling operation or the heating
operation in the system in trouble
(only in one system).
Cooling-only or Heating-only
Cooling-only
Check that SV1 is ON.
SV1 ON
YES
Check that LEV1 and 2 are
controlling the superheat.
Superheat control OK
YES
Check whether LEV3 is controlling
superheat.
Superheat control OK
YES
Check that VB3 is in the
standard position.
VB3:
standard position
YES
Check that VB3 is controlling the
water temperature difference.
Water temperature control OK
YES
Completed
1) Refer to Chapter "Control" for superheat, subcool, and water temperature difference.
HWE1708A
NO
Repair the fault.
Heating-only
NO
Note 1
Check SV1.
NO
Check LEV1.
Note 1
NO
Check LEV3.
NO
Check VB3.
NO
Check VB3.
Check that SV1 is OFF.
NO
NO
Check that LEV3 is fully open.
NO
Check that VB3 is in the
NO
Check that VB3 is controlling the
water temperature difference.
NO
Water temperature control OK
- 191 -
SV1 OFF
YES
Note 1
Subcool control OK
YES
Note 1
LEV3: fully open
YES
standard position.
VB3:
standard position
YES
YES
GB